title: Hearing aid

text: These 'hearing glasses' incorporate a directional microphone capability: four microphones on each side of the frame effectively work as two directional microphones, which are able to discern between sound coming from the front and sound coming from the sides or back of the user. This improves the signal-to-noise ratio by allowing for amplification of the sound coming from the front, the direction in which the user is looking, and active noise control for sounds coming from the sides or behind.


title: Hearing aid

text: Only very recently has the technology required become small enough to be fitted in the frame of the glasses. As a recent addition to the market, this new hearing aid is currently available only in the Netherlands and Belgium.


title: Hearing aid

text: These hearing aids are designed for medical practitioners with hearing loss who use stethoscopes. The hearing aid is built into the speaker of the stethoscope, which amplifies the sound.


title: Hearing aid

text: Hearing aid applications (HAA) are software which, when installed on mobile computational platforms, transforms them into hearing aids.


title: Hearing aid

text: The principle of HAA operation corresponds to the basic principles of operation of traditional hearing aids: the microphone receives an acoustic signal and converts it into a digital form. Sound amplification is achieved by the means of a mobile computational platform, in accordance with the degree and type of the user's hearing loss. The processed audio signal is transformed into an audio signal and output to the user into the headphones/headset. Signal processing is implemented in real time.


title: Hearing aid

text: Constructional features of mobile computational platforms imply preferred use of stereo headsets with two speakers, which allows carrying out binaural hearing correction for the left and right ear separately. HAAs can work with both wired and wireless headsets and headphones.


title: Hearing aid

text: As a rule, HAAs have two operation modes: setup mode and hearing aid mode. Setup mode involves the user passing an in situ-audiometry procedure, which determines the user's hearing characteristics. Hearing aid mode is a hearing correction system that corrects the user's hearing in accordance with the user's hearing thresholds. HAAs also incorporate background noise suppression and acoustic feedback suppression.


title: Hearing aid

text: The user can independently choose a formula to enhance the sound, as well as adjust the level of the desired amplification to their wishes.


title: Hearing aid

text: The first electrical hearing aid used the carbon microphone of the telephone and was introduced in 1896. The vacuum tube made electronic amplification possible, but early versions of amplified hearing aids were too heavy to carry around. Miniaturization of vacuum tubes lead to portable models, and after World War II, wearable models using miniature tubes. The transistor invented in 1948 was well suited to the hearing aid application due to low power and small size; hearing aids were an early adopter of transistors. The development of integrated circuits allowed further improvement of the capabilities of wearable aids, including implementation of digital signal processing techniques and programmability for the individual user's needs.


title: Hearing aid

text: A hearing aid and a telephone are "compatible" when they can connect to each other in a way that produces clear, easily understood sound. The term "compatibility" is applied to all three types of telephones (wired, cordless, and mobile). There are two ways telephones and hearing aids can connect with each other:


title: Hearing aid

text: Note that telecoil coupling has nothing to do with the radio signal in a cellular or cordless phone: the audio signal picked up by the telecoil is the weak electromagnetic field that is generated by the voice coil in the phone's speaker as it pushes the speaker cone back and forth.


title: Hearing aid

text: The electromagnetic (telecoil) mode is usually more effective than the acoustic method. This is mainly because the microphone is often automatically switched off when the hearing aid is operating in telecoil mode, so background noise is not amplified. Since there is an electronic connection to the phone, the sound is clearer and distortion is less likely. But in order for this to work, the phone has to be hearing-aid compatible. More technically, the phone's speaker has to have a voice coil that generates a relatively strong electromagnetic field. Speakers with strong voice coils are more expensive and require more energy than the tiny ones used in many modern telephones; phones with the small low-power speakers cannot couple electromagnetically with the telecoil in the hearing aid, so the hearing aid must then switch to acoustic mode. Also, many mobile phones emit high levels of electromagnetic noise that creates audible static in the hearing aid when the telecoil is used. A workaround that resolves this issue on many mobile phones is to plug a wired (not Bluetooth) headset into the mobile phone; with the headset placed near the hearing aid the phone can be held far enough away to attenuate the static. Another method is to use a "neckloop" (which is like a portable, around-the-neck induction loop), and plug the neckloop directly into the standard audio jack (headphones jack) of a smartphone (or laptop, or stereo, etc.). Then, with the hearing aids' telecoil turned on (usually a button to press), the sound will travel directly from the phone, through the neckloop and into the hearing aids' telecoils.


title: Hearing aid

text: On 21 March 2007, the Telecommunications Industry Association issued the TIA-1083 standard, which gives manufacturers of cordless telephones the ability to test their products for compatibility with most hearing aids that have a T-Coil magnetic coupling mode. With this testing, digital cordless phone manufacturers will be able to inform consumers about which products will work with their hearing aids.


title: Hearing aid

text: The American National Standards Institute (ANSI) has a ratings scale for compatibility between hearing aids and phones:


title: Hearing aid

text: The best possible rating is M4/T4 meaning that the phone works well in both modes. Devices rated below M3 are unsatisfactory for people with hearing aids.


title: Hearing aid

text: Computer programs that allow the creation of a hearing aid using a PC, tablet or smartphone are currently gaining in popularity. Modern mobile devices have all the necessary components to implement this: hardware (an ordinary microphone and headphones may be used) and a high-performance microprocessor that carries digital sound processing according to a given algorithm.


title: Hearing aid

text: Application configuration is carried out by the user himself in accordance with the individual features of his hearing ability. The computational power of modern mobile devices is sufficient to produce the best sound quality. This, coupled with software application settings (for example, profile selection according to a sound environment) provides for high comfort and convenience of use.


title: Hearing aid

text: It should be clearly understood that "hearing aid" application for smartphone / tablet cannot be considered a complete substitution of a digital hearing aid, since the latter:


title: Hearing aid

text: Functionality of hearing aid applications may involve a hearing test (in situ audiometry) too. However, the results of the test are used only to adjust the device for comfortable working with the application. The procedure of hearing testing in any way cannot claim to replace an audiometry test carried out by a medical specialist, so cannot be a basis for diagnosis.


title: Hearing aid

text: Recent hearing aids include wireless hearing aids. One hearing aid can transmit to the other side so that pressing one aid's program button simultaneously changes the other aid, so that both aids change background settings simultaneously. FM listening systems are now emerging with wireless receivers integrated with the use of hearing aids. A separate wireless microphone can be given to a partner to wear in a restaurant, in the car, during leisure time, in the shopping mall, at lectures, or during religious services. The voice is transmitted wirelessly to the hearing aids eliminating the effects of distance and background noise. FM systems have shown to give the best speech understanding in noise of all available technologies.


title: Hearing aid

text: 2.4 gigahertz Bluetooth connectivity is the most recent innovation in wireless interfacing for hearing instruments to audio sources such as TV streamers or Bluetooth enabled mobile phones. Current hearing aids generally do not stream directly via Bluetooth but rather do so through a secondary streaming device (usually worn around the neck or in a pocket), this bluetooth enabled secondary device then streams wirelessly to the hearing aid but can only do so over a short distance. This technology can be applied to ready-to-wear devices (BTE, Mini BTE, RIE, etc.) or to custom made devices that fit directly into the ear.


title: Hearing aid

text: In developed countries FM systems are considered a cornerstone in the treatment of hearing loss in children. More and more adults discover the benefits of wireless FM systems as well, especially since transmitters with different microphone settings and Bluetooth for wireless cell phone communication have become available.


title: Hearing aid

text: Many theatres and lecture halls are now equipped with assistive listening systems that transmit the sound directly from the stage; audience members can borrow suitable receivers and hear the program without background noise. In some theatres and churches FM transmitters are available that work with the personal FM receivers of hearing instruments.


title: Hearing aid

text: Most older hearing aids have only an omnidirectional microphone. An omnidirectional microphone amplifies sounds equally from all directions. In contrast, a directional microphone amplifies sounds from one direction more than sounds from other directions. This means that sounds originating from the direction the system is steered toward are amplified more than sounds coming from other directions. If the desired speech arrives from the direction of steering and the noise is from a different direction, then compared to an omnidirectional microphone, a directional microphone provides a better signal-to-noise ratio. Improving the signal-to-noise ratio improves speech understanding in noise. Directional microphones have been found to be the second best method to improve the signal-to-noise ratio (the best method was an FM system, which locates the microphone near the mouth of the desired talker).


title: Hearing aid

text: Many hearing aids have both an omnidirectional and a directional microphone mode. This is because the wearer may not need or desire the noise-reducing properties of the directional microphone in a given situation. Typically, the omnidirectional microphone mode is used in quiet listening situations (e.g. living room) whereas the directional microphone is used in noisy listening situations (e.g. restaurant). The microphone mode is typically selected manually by the wearer. Some hearing aids automatically switch the microphone mode.


title: Hearing aid

text: Adaptive directional microphones automatically vary the direction of maximum amplification or rejection (to reduce an interfering directional sound source). The direction of amplification or rejection is varied by the hearing aid processor. The processor attempts to provide maximum amplification in the direction of the desired speech signal source or rejection in the direction of the interfering signal source. Unless the user manually temporarily switches to a "restaurant program, forward only mode" adaptive directional microphones frequently amplify the speech of other talkers in a cocktail party type environments, such as restaurants or coffee shops; this can also be helpful during business meetings. The presence of multiple speech signals makes it difficult for the processor to correctly select the desired speech signal. Another disadvantage is that some noises often contain characteristics similar to speech, making it difficult for the hearing aid processor to distinguish the speech from the noise. Despite the disadvantages, adaptive directional microphones can provide improved speech recognition in noise.


title: Hearing aid

text: FM systems have been found to provide a better signal-to-noise ratio even at larger speaker-to-talker distances in simulated testing conditions.


title: Hearing aid

text: Telecoils or T-coils (from "Telephone Coils") are small devices installed in hearing aids or cochlear implants. An audio induction loop generates an electromagnetic field that can be detected by T-coils, allowing audio sources to be directly connected to a hearing aid. The T-coil is intended to help the wearer filter out background noise. They can be used with telephones, FM systems (with neck loops), and induction loop systems (also called "hearing loops") that transmit sound to hearing aids from public address systems and TVs. In the UK and the Nordic countries, hearing loops are widely used in churches, shops, railway stations, and other public places. In the US, telecoils and hearing loops are gradually becoming more common. Audio induction loops, telecoils and hearing loops are gradually becoming more common also in Slovenia.


title: Hearing aid

text: A T-coil consists of a metal core (or rod) around which ultra-fine wire is coiled. T-coils are also called induction coils because when the coil is placed in a magnetic field, an alternating electric current is induced in the wire (Ross, 2002b; Ross, 2004). The T-coil detects magnetic energy and transduces (converts) it to electrical energy. In the United States, the Telecommunications Industry Association's TIA-1083 standard, specifies how analog handsets can interact with telecoil devices, to ensure the optimal performance.


title: Hearing aid

text: Although T-coils are effectively a wide-band receiver, interference is unusual in most hearing loop situations. Interference can manifest as a buzzing sound, which varies in volume depending on the distance the wearer is from the source. Sources are electromagnetic fields, such as CRT computer monitors, older fluorescent lighting, some dimmer switches, many household electrical appliances and airplanes.


title: Hearing aid

text: The states of Florida and Arizona have passed legislation that requires hearing professionals to inform patients about the usefulness of telecoils.


title: Hearing aid

text: In the United States, the Hearing Aid Compatibility Act of 1988 requires that the Federal Communications Commission (FCC) ensure that all telephones manufactured or imported for use in the United States after August 1989, and all "essential" telephones, be hearing aid-compatible (through the use of a telecoil).


title: Hearing aid

text: "Essential" phones are defined as "coin-operated telephones, telephones provided for emergency use, and other telephones frequently needed for use by persons using such hearing aids." These might include workplace telephones, telephones in confined settings (like hospitals and nursing homes), and telephones in hotel and motel rooms. Secure telephones, as well as telephones used with public mobile and private radio services, are exempt from the HAC Act. "Secure" phones are defined as "telephones that are approved by the U.S. Government for the transmission of classified or sensitive voice communications."


title: Hearing aid

text: In 2003, the FCC adopted rules to make digital wireless telephones compatible with hearing aids and cochlear implants. Although analog wireless phones do not usually cause interference with hearing aids or cochlear implants, digital wireless phones often do because of electromagnetic energy emitted by the phone's antenna, backlight, or other components. The FCC has set a timetable for the development and sale of digital wireless telephones that are compatible with hearing aids. This effort promises to increase the number of digital wireless telephones that are hearing aid-compatible. Older generations of both cordless and mobile phones used analog technology.


title: Hearing aid

text: An audio boot or audio shoe is an electronic device used with hearing aids; hearing aids often come with a special set of metal contacts for audio input. Typically the audio boot will fit around the end of the hearing aid (a behind-the-ear model, as in-the-ear do not afford any purchase for the connection) to link it with another device, like an FM system or a cellphone or even a digital audio player.


title: Hearing aid

text: Direct audio input (DAI) allows the hearing aid to be directly connected to an external audio source like a CD player or an assistive listening device (ALD). By its very nature, DAI is susceptible to far less electromagnetic interference, and yields a better quality audio signal as opposed to using a T-coil with standard headphones. An audio boot is a type of device that may be used to facilitate DAI.


title: Hearing aid

text: Every electronic hearing aid has at minimum a microphone, a loudspeaker (commonly called a receiver), a battery, and electronic circuitry. The electronic circuitry varies among devices, even if they are the same style. The circuitry falls into three categories based on the type of audio processing (analog or digital) and the type of control circuitry (adjustable or programmable). Hearing aid devices generally do not contain processors strong enough to process complex signal algorithms for sound source localization.


title: Hearing aid

text: Digital audio, programmable control: Both the audio circuit and the additional control circuits are fully digital. The hearing professional programs the hearing aid with an external computer temporarily connected to the device and can adjust all processing characteristics on an individual basis. Fully digital circuitry allows implementation of many additional features not possible with analog circuitry, can be used in all styles of hearing aids and is the most flexible; for example, digital hearing aids can be programmed to amplify certain frequencies more than others, and can provide better sound quality than analog hearing aids. Fully digital hearing aids can be programmed with multiple programs that can be invoked by the wearer, or that operate automatically and adaptively. These programs reduce acoustic feedback (whistling), reduce background noise, detect and automatically accommodate different listening environments (loud vs. soft, speech vs. music, quiet vs. noisy, etc.), control additional components such as multiple microphones to improve spatial hearing, transpose frequencies (shift high frequencies that a wearer may not hear to lower frequency regions where hearing may be better), and implement many other features. Fully digital circuitry also allows control over wireless transmission capability for both the audio and the control circuitry. Control signals in a hearing aid on one ear can be sent wirelessly to the control circuitry in the hearing aid on the opposite ear to ensure that the audio in both ears is either matched directly or that the audio contains intentional differences that mimic the differences in normal binaural hearing to preserve spatial hearing ability. Audio signals can be sent wirelessly to and from external devices through a separate module, often a small device worn like a pendant and commonly called a "streamer", that allows wireless connection to yet other external devices. This capability allows optimal use of mobile telephones, personal music players, remote microphones and other devices. With the addition of speech recognition and internet capability in the mobile phone, the wearer has optimal communication ability in many more situations than with hearing aids alone. This growing list includes voice activated dialing, voice activated software applications either on the phone or on the internet, receipt of audio signals from databases on the phone or on internet, or audio signals from television sets or from global positioning systems. The first practical, wearable, fully digital hearing aid was invented by Maynard Engebretson, Robert E Morley, Jr. and Gerald R Popelka. Their work resulted in US Patent 4,548,082, "Hearing aids, signal supplying apparatus, systems for compensating hearing deficiencies, and methods" by A Maynard Engebretson, Robert E Morley, Jr. and Gerald R Popelka, filed in 1984. This patent formed the basis of all subsequent fully digital hearing aids from all manufacturers, including those produced currently.


title: Hearing aid

text: The signal processing is performed by the microprocessor in real time and taking into account the individual preferences of the user (for example, increasing bass for better speech perception in noisy environments, or selective amplification of high frequencies for people with reduced sensibility to this range). The microprocessor automatically analyzes the nature of the external background noise and adapts the signal processing to the specific conditions (as well as to its change, for example, when the user goes outside from the building).


title: Hearing aid

text: In speech enhancement, for example using neural networks, finds application in hearing aids. Problems may arise if these methods filter out emergency sounds such as fire alarms and car horns.


title: Hearing aid

text: Analogue hearing aids make all the sounds picked up by the microphone louder. For example, speech and ambient noise will be made louder together. On the other hand, digital hearing aid (DHA) technology processes the sound using digital technology. Before transmitting the sound to the speaker, the DHA microprocessor processes the digital signal received by the microphone according to an algorithm. This allows certain-frequency sounds to be made louder according to the individual user's settings (personal audiogram), and the DHA can automatically adjust to various environments (noisy streets, quiet room, concert hall, etc.).


title: Hearing aid

text: For users with varying degrees of hearing loss, it is difficult to perceive the entire frequency range of external sounds. DHAs with multi-channel digital processing allow a user to "compose" the output sound by fitting a whole spectrum of the input signal into it. This gives users with limited hearing abilities the opportunity to perceive the whole range of ambient sounds, despite the personal difficulties of perception of certain frequencies. Moreover, even in this "narrow" range the DHA microprocessor is able to emphasize desired sounds (e.g. speech), lowering unwanted loud, high, etc., sounds at the same time.


title: Hearing aid

text: According to research DHAs have a number of significant advantages compared to analogue hearing aids:


title: Hearing aid

text: These advantages of DHAs were confirmed by a number of studies relating to the comparative analysis of digital hearing aids of second and first generations and analog hearing aids.


title: Hearing aid

text: Smartphones have all the necessary hardware to perform the functions of a digital hearing aid: microphone, AD converter, digital processor, DA converter, amplifier, and speakers. External microphone and speakers can also be connected as a special headset.


title: Hearing aid

text: The operational principles of hearing aid applications correspond to general operational principles of digital hearing aids: the microphone perceives an acoustic signal and converts it to digital form. Sound amplification is achieved through hardware and software in accordance with the user's hearing characteristics. Then, the signal is converted to analog form and received in the headphones by the user. The signal is processed in real time.


title: Hearing aid

text: Stereo headsets with two speakers can be used, which allows separate binaural hearing correction for the left and right ear.


title: Hearing aid

text: Unlike digital hearing aids, the adjustment of hearing aid applications is an integral part of the application itself. Hearing aid applications are adjusted in accordance with the user's audiogram. The whole adjustment process is automated so that the user can perform audiometry on their own.


title: Hearing aid

text: The hearing correction application has two modes: audiometry and correction. In the audiometry mode, hearing thresholds are measured. In the correction mode, the signal is processed with respect to the obtained thresholds.


title: Hearing aid

text: Hearing aid applications also provide for different computational formulas for the calculation of sound amplification based on the audiometry data. These formulas are intended for maximum comfortable speech amplification and best sound intelligibility.


title: Hearing aid

text: Hearing aid applications allow the user to save different user profiles for different acoustic environments. Thus, in contrast to the static settings of digital hearing aids, the user can quickly switch between the profiles depending on the acoustic environment.


title: Hearing aid

text: One of the most important characteristics of the hearing aid is acoustic feedback. In hearing aid applications, there is a significant hardware delay, so hearing aid applications use a signal processing scheme with the minimum possible algorithmic delay to make it as short as possible.


title: Hearing aid

text: Personal sound amplification products (PSAP) are classified by the FDA as "personal sound amplification devices". These compact electronic devices are designed for people without hearing loss. Unlike hearing aids (which the FDA classifies as devices to compensate for hearing impairment), the use of PSAP does not require a medical prescription. Such devices are used by hunters, naturalists (for audio observation of animals or birds), ordinary people (for example, to increase the volume of the TV in a quiet room), etc. PSAP models differ significantly in price and functionality. Some devices simply amplify sound. Others contain directional microphones, equalizers to adjust the audio signal gain and filter noise. In modern days, some people refer to these devices as OTC hearing aids.


title: Hearing aid

text: There are audio players designed specifically for the hard-of-hearing. These applications amplify the volume of the reproduced audio signal in accordance with the user's hearing characteristics and act as a music volume amplifier and assistive hearing aid. The amplification algorithm works on the frequencies that the user hears worse, thus restoring natural hearing perception of the sound of music.


title: Hearing aid

text: There are also applications that not only adapt the sound of music but also include some hearing aid functions. Such applications include a sound amplification mode in accordance with the user's hearing characteristics as well as a noise suppression mode and a mode allowing the user to hear ambient sound without pausing the music.


title: Hearing aid

text: Also, some applications allow the hard-of-hearing to watch video and listen to the radio with comfort. The operational principles of these applications are similar to those of hearing aid applications: the audio signal is amplified on the frequencies that the user hears worse.


title: Hearing aid

text: A person using a hearing aid for the first time often cannot make use of all its advantages quickly. The structure and characteristics of hearing aids are thoroughly devised by specialists in order to make the adjustment period as simple and quick as possible. However, despite this, a beginning hearing aid user certainly needs time to get used to it.


title: Hearing aid

text: Due to the plasticity of the central nervous system, inactive hearing centers in the brain's cortex switch over to processing auditory stimuli in another frequency and intensity. The brain starts to perceive sounds amplified by the hearing aid immediately after the initial adjustment; however, it may not process them correctly right away.


title: Hearing aid

text: Feeling the hearing aid in the ear may seem unusual. It also takes time to adapt to a new way of hearing. The ear has to be gradually adjusted to the new sound. The sound may seem unnatural, metallic, too loud or too quiet. A whistling sound may also appear, which can be unpleasant.


title: Hearing aid

text: Hearing aids do not provide immediate improvement. The adjustment period can last from several hours to several months.


title: Hearing aid

text: Patients are offered an initial schedule to wear their hearing aid, ensuring gradual adaptation to it. If the patient wears the hearing aid continually from the beginning, the unfamiliar sound may cause a headache, and as a result, the user may refuse to wear a hearing aid despite the fact that it helps. Audiologists often run a quick preparation course for the patients. As a rule, users have inflated expectations of hearing aids. They expect that hearing aids will help them to hear in the same way as before hearing loss, but it is not the case. Training sessions help hearing aid users to get accustomed to the feeling of new sounds. Users are strongly recommended to regularly visit an audiologist, including for the purposes of additional hearing aid adjustment.


title: Hearing aid

text: Hearing aid applications, in contrast to traditional hearing aids, allow the implementation of options such as a built-in adaptation course.


title: Hearing aid

text: The adaptation course includes a certain number of stages, starting from listening to a set of low everyday sounds in a quiet environment, getting accustomed to one's own speech and other people's speech, getting accustomed to speech among background noise, etc.


title: Hearing aid

text: The first hearing aids were ear trumpets, and were created in the 17th century. Some of the first hearing aids were external hearing aids. External hearing aids directed sounds in front of the ear and blocked all other noises. The apparatus would fit behind or in the ear.


title: Hearing aid

text: The movement toward modern hearing aids began with the creation of the telephone, and the first electric hearing aid, the "akouphone", was created about 1895 by Miller Reese Hutchison. By the late 20th century, digital hearing aids were commercially available.


title: Hearing aid

text: The invention of the carbon microphone, transmitters, digital signal processing chip or DSP, and the development of computer technology helped transform the hearing aid to its present form.


title: Hearing aid

text: The history of DHA can be divided into three stages. The first stage began in the 1960s with the widespread use of digital computers for simulation of audio processing and for the analysis of systems and algorithms. The work was conducted with the help of the very large digital computers of that era. These efforts were not actual digital hearing aids because the computers were not fast enough for audio processing in real time and their size prevented them from being described as wearable, but they allowed successful studies of the various hardware circuits and algorithms for digital processing of audio signals. The software package Block of Compiled Diagrams (BLODI) developed by Kelly, Lockbaum and Vysotskiy in 1961 allowed simulation of any sound system that could be characterized in the form of a block diagram. A special phone was created so that a person with a hearing impairment could listen to the digitally processed signals, but not in real time. In 1967, Harry Levitt used BLODI to simulate a hearing aid on a digital computer.


title: Hearing aid

text: Almost ten years later the second stage began with the creation of the hybrid hearing aid, in which the analog components of a conventional hearing aid consisting of amplifiers, filters and signal limiting were combined with a separate digital programmable component in a conventional hearing aid case. The audio processing remained analog but it was controlled by the digital programmable component. The digital component could be programmed by connecting the device to an external computer in the laboratory then disconnected to allow the hybrid device to function as a conventional wearable hearing aid.


title: Hearing aid

text: The hybrid device was effective from a practical point of view because of the low power consumption and compact size. At that time, low-power analog amplifier technology was well developed in contrast to the available semiconductor chips able to process digital audio in real time. The combination of high performance analog components for real time audio processing and a separate low power digital programmable component only for controlling the analog signal led to the creation of several low power digital programmable components able to implement different types of control.


title: Hearing aid

text: A hybrid hearing aid was developed by Etymotic Design. A little later, Mangold and Lane created a programmable multi-channel hybrid hearing aid. Graupe with co-authors developed a digital programmable component that implemented an adaptive noise filter.


title: Hearing aid

text: The third stage began in the early 1980s by a research group at Central Institute for the Deaf headed up by faculty members at Washington University in St. Louis MO. This group created the first fully digital wearable hearing aid. They first conceived a complete, comprehensive full digital hearing aid, then designed and fabricated, miniaturized full digital computer chips using custom digital signal processing chips with low power and very large scale integrated (VLSI) chip technology able to process both the audio signal in real time and the control signals, yet able to be powered by a battery and be fully wearable as a full digital wearable hearing aid able to be actually used by individuals with hearing loss in real-world environments. Engebretson, Morley and Popelka were the inventors of the first full digital hearing aid. Their work resulted in US Patent 4,548,082, "Hearing aids, signal supplying apparatus, systems for compensating hearing deficiencies, and methods" by A Maynard Engebretson, Robert E Morley, Jr. and Gerald R Popelka, filed in 1984 and issued in 1985. This full digital wearable hearing aid also included many additional features now used in all contemporary full digital hearing aids including a bidirectional interface with an external computer, self-calibration, self-adjustment, wide bandwidth, digital programmability, a fitting algorithm based on audibility, internal storage of digital programs, and fully digital multichannel amplitude compression and output limiting. This group created several of these full digital hearing aids and used them for research on hearing impaired people as they wore them in the same manner as conventional hearing aids in real-world situations. In this first full DHA all stages of sound processing and control were carried out in binary form. The external sound was picked up by a microphone positioned in an ITE ear module to take advantage of the acoustic effects of the pinna, then converted into binary code, digitally processed and digitally controlled in real time, then converted back to an analog signal sent to two miniature loudspeakers positioned in the same ITE ear module. The ITE module also contained an inward facing microphone to measure the sound actually generated in the ear canal, a precursor to separate probe tube measures now routinely used for hearing aid fitting. The necessary electronic components, including batteries, to support this arrangement were situated in a BTE module that could be supplemented with a body worn module. These specialized hearing aid chips continued to become smaller, increase in computational ability and require even less power. Now, virtually all commercial hearing aids are fully digital and their digital signal processing capability has significantly increased. Very small and very low power specialized digital hearing aid chips are now used in all hearing aids manufactured worldwide. Many additional new features also have been added with various on-board advanced wireless technology.


title: Hearing aid

text: Hearing aids are provided by the state to children, OAPs and to people whose income is at or below that of the state pension. The Irish state hearing aid provision is extremely poor; people often have to wait for two years for an appointment.


title: Hearing aid

text: Hearing aids are also available privately, and there is grant assistance available for insured workers. For the fiscal year ending 2016, the grant stands at a maximum of €500 per ear.


title: Hearing aid

text: Irish taxpayers can also claim tax relief at the standard rate as hearing aids are recognised as a medical device.


title: Hearing aid

text: Ordinary hearing aids are regulated medical devices under Federal Food and Drug Administration (FDA) rules. A 1976 statute explicitly prohibits any state requirement that is "different from, or in addition to, any requirement applicable" to regulated medical devices (which includes hearing aids) which relates "to the safety and effectiveness of the device". Inconsistent state regulation is preempted under the federal law. In the late 1970s, the FDA established federal rules governing hearing aid sales, and addressed various requests by state authorities for exemptions from federal preemption, granting some and denying others. The Over-the-Counter Hearing Aid Act (OTC Act) was passed under the FDA Reauthorization Act of 2017, creating a class of hearing aids regulated by the FDA available directly to consumers without involvement from a licensed professional. This law's provisions are expected to go into effect in 2020.


title: Hearing aid

text: In August 2022, the FDA issued a final rule to improve access to hearing aids. The action establishes a new category of over-the-counter (OTC) hearing aids, enabling consumers with perceived mild to moderate hearing impairment to purchase hearing aids directly from stores or online retailers without the need for a medical exam, prescription or a fitting adjustment by an audiologist. The FDA action amends existing rules that apply to prescription hearing aids for consistency with the new OTC category, it repeals the conditions for sale for hearing aids, and it includes provisions that address some of the effects of the FDA OTC hearing aid regulations on state regulation of hearing aids. The FDA also issued the final guidance, Regulatory Requirements for Hearing Aid Devices and Personal Sound Amplification Products (PSAPs), to clarify the differences between hearing aids, which are medical devices, and PSAPs, consumer products that help people with normal hearing amplify sounds.


title: Hearing aid

text: Several industrialized countries supply free or heavily discounted hearing aids through their publicly funded health care system.


title: Hearing aid

text: The Australian Department of Health and Ageing provides eligible Australian citizens and residents with a basic hearing aid free-of-charge, though recipients can pay a "top up" charge if they wish to upgrade to a hearing aid with more or better features. Maintenance of these hearing aids and a regular supply of batteries is also provided, on payment of a small annual maintenance fee.


title: Hearing aid

text: In Canada, health care is a responsibility of the provinces. In the province of Ontario, the price of hearing aids is partially reimbursed through the Assistive Devices Program of the Ministry of Health and Long-Term care, up to $500 for each hearing aid. Like eye appointments, audiological appointments are no longer covered through the provincial public health plan. Audiometric testing can still easily be obtained, often free of charge, in private sector hearing aid clinics and some ear, nose and throat doctors offices. Hearing aids may be covered to some extent by private insurance or in some cases through government programs such as Veterans Affairs Canada or Workplace Safety & Insurance Board.


title: Hearing aid

text: Social Insurance pays a one time fee of ISK 30,000 for any kind of hearing aid. However, the rules are complicated and require that both ears have significant hearing loss in order to qualify for reimbursement. BTE hearing aids range from ISK 60,000 to ISK 300,000.


title: Hearing aid

text: In India hearing aids of all kinds are easily available. Under central and state government health services, the poor can often avail themselves of free hearing devices. However, market prices vary for others and can range from Rs 10,000 to Rs 275,000 per ear.


title: Hearing aid

text: From 2000 to 2005 the Department of Health worked with Action on Hearing Loss (then called RNID) to improve the quality of NHS hearing aids so every NHS audiology department in England was fitting digital hearing aids by March 2005. By 2003 over 175,000 NHS digital hearing aids had been fitted to 125,000 people. Private companies were recruited to enhance the capacity, and two were appointed – David Ormerod Hearing Centres, partly owned by Alliance Boots and Ultravox Group, a subsidiary of Amplifon.


title: Hearing aid

text: Within the UK, the NHS provides digital BTE hearing aids to NHS patients, on long-term loan, free of charge. Other than BAHAs (bone anchored hearing aid) or cochlear implants, where specifically required, BTEs are usually the only style available. Private purchases may be necessary if a user desires a different style. Batteries are free.


title: Hearing aid

text: In 2014 the Clinical Commissioning Group in North Staffordshire considered proposals to end provision of free hearing aids for adults with mild to moderate age related hearing loss, which currently cost them £1.2m a year. Action on Hearing Loss mobilised a campaign against the proposal.


title: Hearing aid

text: In June 2018 the National Institute for Health and Care Excellence produced new guidance saying that hearing aids should be offered at the first opportunity when hearing loss affects the individual's ability to hear and communicate, rather than waiting for arbitrary thresholds of hearing loss to be reached.


title: Hearing aid

text: Most private healthcare providers in the United States do not provide coverage for hearing aids, so all costs are usually borne by the recipient. The cost for a single hearing aid can vary between $500 and $6,000 or more, depending on the level of technology and whether the clinician bundles fitting fees into the cost of the hearing aid. Though if an adult has hearing loss which substantially limits major life activities, some state-run vocational rehabilitation programs can provide upwards of full financial assistance. Severe and profound hearing loss often falls within the "substantially limiting" category. Less expensive hearing aids can be found on the internet or mail order catalogs, but most in the under-$200 range tend to amplify the low frequencies of background noise, making it harder to hear the human voice.


title: Hearing aid

text: Military veterans receiving VA medical care are eligible for hearing aids based on medical need. The Veterans Administration pays the full cost of testing and hearing aids to qualified military veterans. Major VA medical facilities provide complete diagnostic and audiology services.


title: Hearing aid

text: The cost of hearing aids is a tax-deductible medical expense for those who itemize medical deductions.


title: Hearing aid

text: Research involving more than 40,000 US households showed a convincing correlation between the degree of hearing loss and the reduction of personal income. According to the same research, the tendency was not observed in almost 100% of households using DHA.


title: Hearing aid

text: While there are some instances that a hearing aid uses a rechargeable battery or a long-life disposable battery, the majority of modern hearing aids use one of five standard button cell zinc–air batteries. (Older hearing aids often used mercury battery cells, but these cells have become banned in most countries today.) Modern hearing aid button cell types are typically referred to by their common number name or the color of their packaging.


title: Hearing aid

text: They are typically loaded into the hearing aid via a rotating battery door, with the flat side (case) as the positive terminal (cathode) and the rounded side as the negative terminal (anode).


title: Hearing aid

text: The type of battery a specific hearing aid utilizes depends on the physical size allowable and the desired lifetime of the battery, which is in turn determined by the power draw of the hearing aid device. Typical battery lifetimes run between 1 and 14 days (assuming 16-hour days).


title: V.

text: V. is the debut novel of Thomas Pynchon, published in 1963. It describes the exploits of a discharged U.S. Navy sailor named Benny Profane, his reconnection in New York with a group of pseudo-bohemian artists and hangers-on known as the Whole Sick Crew, and the quest of an aging traveler named Herbert Stencil to identify and locate the mysterious entity he knows only as "V." It was nominated for a National Book Award.


title: V.

text: The novel alternates between episodes featuring Benny, Stencil and other members of the Whole Sick Crew (including Profane's sidekick Pig Bodine) in 1956 (with a few minor flashbacks), and a generation-spanning plot that comprises Stencil's attempts to unravel the clues he believes will lead him to "V." (or to the various incarnations thereof). Each of these "Stencilised" chapters is set at a different moment of historical crisis; the framing narrative involving Stencil, "V.", and the journals of Stencil's British spy/diplomat father threads the sequences together. The novel's two storylines increasingly converge in the last chapters (the intersecting lines forming a V-shape, as it were), as Stencil hires Benny to travel with him to Malta.


title: V.

text: The opening chapter is set in Norfolk, Virginia, on Christmas Eve, 1955. Benny Profane, a recently discharged seaman, is at a local sailor bar called the "Sailor's Grave" in which every waitress is named Beatrice and the beer taps are rubber model breasts that the sailors suck on. Here Profane meets Ploy, a short violent sailor, his musician friend Dewey Gland, and the Maltese barmaid Paola Hod. Bar owner Mrs. Buffo begins to play a rendition of "It Came Upon the Midnight Clear" to celebrate Christmas only to be immediately assaulted by Ploy and the rest of the intoxicated sailors. The disorder triggers a raid by the military police. Pig Bodine, Paola, Dewey Gland and Profane escape the chaos to Pig's apartment.


title: V.

text: The chapter opens with Rachel Owlglass confronting the plastic surgeon Shale Schoenmaker whom she accuses of manipulating her friend and roommate Esther Havitz into debt through repeated rhinoplasty. Schoenmaker responds by entering into a monologue on the nature of Jewish women and the nature of appearance.


title: V.

text: Section II is set during a party at Rachel's apartment attended by the "Sick Crew", Paola, Esther, and Debb. This section introduces the character Herbert Stencil, a troubled man who is obsessed with his father's mysterious death in Malta (even more mysterious as Sidney Stencil, Herbert's father, was a British secret agent) and the identity of "V", a woman mentioned in his journal.


title: V.

text: This chapter, set among the British community in Egypt toward the end of the 19th century, consists of an introduction and a series of eight relatively short sections, each of them from the point of view of a different person. The eight sections come together to tell a story of murder and intrigue, intersecting the life of a young woman, Victoria Wren, the first incarnation of V. The title is a hint as to how this chapter is to be understood: Stencil imagines each of the eight viewpoints as he reconstructs—we do not know on how much knowledge and how much conjecture—this episode. This chapter is a reworking of Pynchon's short story "Under the Rose", which was first published in 1961 and is collected in "Slow Learner" (1984). In the "Slow Learner" introduction, Pynchon admits he took the details of the setting ("right down to the names of the diplomatic corps") from Karl Baedeker's 1899 travel guide for Egypt. Stencil's reconstruction follows the same basic conflict as "Under the Rose", but it gives the non-European characters much more personality.


title: V.

text: Section I details the history of Shale Schoenmaker, M.D. and how he began his career as a plastic surgeon. During World War I he eagerly enlists in the A.E.F. hoping to become a pilot but, is instead given a position as an engineer. While serving he witnesses Evan Godolphin, a handsome pilot whom he idealized, become horribly disfigured during an air raid. A month later Schoenmaker visits Godolphin in the hospital while he is recovering from reconstructive surgery, discovering that an incompetent surgeon, Halidom, treated him using the archaic method that would inevitably lead to further disfigurement by infection. This event traumatizes Schoenmaker, causing him to now see it as his mission to help people like Godolphin, a conviction that slowly decays over time.


title: V.

text: Stencil comes across Schoenmaker in his search for V. and refers Esther to him for her nose job. At a follow-up appointment Esther and Schoenmaker become lovers.


title: V.

text: Only marginally part of the Stencil/V. material, this chapter follows Benny and others, as Benny has a job hunting alligators in the sewers under Manhattan. It figures in the Stencil/V. story in that there is a rat named "Veronica" who figures in a subplot about a mad priest — Father Linus Fairing, S.J. — some decades back, living in the sewers and preaching to the rats; we hear from him in the form of his diary. Stencil himself makes a brief appearance toward the end of the chapter.


title: V.

text: The chapter follows Profane, Geronimo, Angel, and his sister Josephine "Fina" into the city over several nights of drinking. Fina and Profane's relationship develops amid concerns over her status within a local mercenary street gang known as the Playboys, who see her as a spiritual figurehead. The chapter ends amid a massive brawl, nearby which Fina is found lying naked and smiling.


title: V.

text: In Florence in 1899, Victoria appears again, briefly, but so does the place name "Vheissu", which may or may not stand for Vesuvius, Venezuela, a crude interpretation of "wie heißt du", translating into "who are you" in the German language, or even (one character jokes) Venus. The chapter also revolves around an attempted burglary of Botticelli's "The Birth of Venus" by Hugh Godolphin through the Venezuelan consulate.


title: V.

text: The chapter begins with Benny Profane, freshly unemployed after being laid-off from sewer-alligator hunting, in search of a job in Manhattan. After briefly contemplating the nature of money on a park bench, he, by chance, looks at an advertisement issued by The Time/Space Employment Agency. Once arriving at the agency he finds, much to his annoyance, that the secretary is his former lover Rachel Owlglass. In section IV Stencil continues his investigation of the perplexing "V." (whom he now believes is either Victoria or the rat Veronica) meeting up with a Yoyodyne engineer Kurt Mondaugen.


title: V.

text: Kurt Mondaugen, who will appear again in "Gravity's Rainbow", is the central character in a story set in South West Africa (now Namibia) partly during a siege in 1922 at which one Vera Meroving is present, but most notably in 1904, during the Herero Wars, when South West Africa was a German colony.


title: V.

text: McClintic Sphere, an alto sax player in a jazz band, returns home to his boarding house in Harlem. The previous week, spent playing primarily for condescending, snobby Ivy League students, has left him exhausted, and he relaxes in his room with a prostitute named Ruby. Benny, meanwhile, finally gets a job at Anthroresearch Associates, where he's introduced to SHROUD, a synthetic humanoid with whom he holds imaginary conversations. Pig Bodine and Roony Winsome get into a fight, based on Roony's suspicion that Pig is involved with his (Roony's) wife, Mafia. Meanwhile, Mafia aggressively pursues sex with Benny, who declines. Schoenmaker and Esther get into a few arguments because he says he wants to bring out her inner beauty by performing more plastic surgery on her. The chapter finishes out with the Whole Sick Crew hanging out in various places: Sheridan Square, the Rusty Spoon, Slab in front of his Cheese Danish No. 35 canvas. Stencil, looking for Rachel at her apartment, comes upon Paola who gives him the Confessions of Fausto Maijstral.


title: V.

text: Fausto Maijstral, Maltese civilian suffering under the German bombardment and working to clear the rubble during World War II writes a long letter to his daughter Paola, who figures in the Benny Profane story; the letter comes into Stencil's hands. The letter includes copious quotations from Fausto's diary. Besides the place name Valletta, V. figures in the story as an old — or possibly not-so-old — woman crushed by a beam of a fallen building.


title: V.

text: Roony and Mafia continue fighting, so Roony meets up with McClintic at the V-Note, and they travel to Lenox, Massachusetts. Returning to Matilda's boardinghouse, they meet up with Ruby, who Roony recognizes as being a member of the Crew in disguise. Esther tells Slab she is pregnant. He wants to send her to Cuba to get an abortion, and raises the money by announcing his intentions and asking for money at a party the Crew is throwing in an abandoned warehouse. Roony's attempts to deal with his wife then take a dark turn, but he is saved by Pig. At an airport, Esther and Slab attempt to catch Esther a flight to Cuba, but meet some resistance. Paola, traveling with McClintic, reveals her true identity to him. He delivers the line, "Keep cool, but care," considered the novel's central theme, as they drive off into the Berkshires.


title: V.

text: Benny loses his job at Anthroresearch Associates by sleeping in and not being at work to notify the attendant technician that several calamities have occurred in the lab. Rachel nudges him to get a new job, and says that she will find one for him herself. An amusing story unfolds about Benny and Pig during their "Scaffold" days. Benny, unable and unwilling to get work, instead takes a self-described vacation and chooses to spend his spare time at the Rusty Spoon. He gets drunk with Stencil, who relates the entirety of his knowledge of V. as it stands to this point in the novel. Valletta being the last place on Stencil's journey to find information about V., he asks Benny to accompany him and Paola to the island. Benny and Stencil commit a robbery in perilous circumstances, and then, in late September, they embark for Malta with Paola on board the "Susanna Squaducci".


title: V.

text: In this chapter V. is entranced by a young ballerina, Mélanie l'Heuremaudit. The story centers on a riotous ballet performance, almost certainly modeled in part on the premiere of Igor Stravinsky's "The Rite of Spring". The performance centers on a virgin sacrifice by impalement. The young ballerina fails to wear her protective equipment and actually dies by impalement in the course of the performance; everyone assumes her death throes simply to be an uncharacteristically emotional performance.


title: V.

text: Benny and Pig Bodine have one last adventure with two girls, Flip and Flop, as they all get drunk and wander around Washington D.C.. There are two going away parties for Benny, and the chapter ends with Benny, Stencil, and Paola leaving for Malta aboard the "Susanna Squaducci" as the Crew looks on and says goodbye.


title: V.

text: As the Royal Navy mass on Malta in the early stages of the Suez Crisis, Stencil arrives with Benny in tow, searching for Fausto Maijstral. (As always, Kilroy was here first, and Pynchon proposes a novel origin for the face: that Kilroy was originally a schematic for part of a band-pass filter.)


title: V.

text: The last chapter is a flashback to Valletta when Stencil, Sr. was still alive. After World War I he is sent to Malta to observe the various crises going on involving the natives and their desire for independence. He is implored by Maijstral's wife (who is pregnant with Fausto) to relieve him of his duties as a double agent because she fears for his life. Stencil, Sr. meets Veronica Manganese or V and implicitly has sex with her (she is now largely made up of artificial limbs). It is revealed they had trysted in Florence after the riots. He finds out that Maijstral is having an affair with her as well.


title: V.

text: Linus Fairing is also working as a double agent for Stencil, and when he leaves for America, having tired of the life of a spy, Stencil's purpose for being in Malta is null.


title: V.

text: Stencil sails off into the Mediterranean and a waterspout blows the ship up into the air, then down into the depths, not too dissimilar from the conclusion of another American masterpiece, "Moby-Dick", also a sailor's story.


title: V.

text: "Time" wrote "In this sort of book, there is no total to arrive at. Nothing makes any waking sense. But it makes a powerful, deeply disturbing dream sense. Nothing in the book seems to have been thrown in arbitrarily, merely to confuse, as is the case when inept authors work at illusion. Pynchon appears to be indulging in the fine, pre-Freudian luxury of dreams dreamt for the dreaming. The book sails with majesty through caverns measureless to man. What does it mean? Who, finally, is V.? Few books haunt the waking or the sleeping mind, but this is one. Who, indeed?"


title: V.

text: Tony Tanner considered the novel an exploration of the plots individuals ascribe to the ambivalent universe they have no choice but to confront, during a 20th-century period in which genuine communication between individuals has been eroded and in which ambiguous societal forces are at work (intentionally or inadvertently) towards a state of entropy; "SHROUD asks, 'Has it occurred to you there may be no more standards for crazy or sane, now that it's started?' And Benny answers, 'What, for Christ's sake?' What the 'it' is that has started (if there is an 'it'), what common process links remote imperialist incidents with contemporary automation, tourism, Hitler, and the Whole Sick Crew (if there is any linking common process)—this is what the whole book is about."


title: V.

text: Writing in "The New York Times", George Plimpton called Pynchon "a young writer of staggering promise", lauding his "vigorous and imaginative style", "robust humor" and "tremendous reservoir of information".


title: V.

text: There is an interesting connection to "So Many Doors", a 1951 crime novel written by Oakley Hall, an author for whom Pynchon has expressed admiration. In that novel a character named Vasilia Baird is murdered and it is revealed that many suspects knew her only as "V."


title: V.

text: In 2012 it emerged that there were multiple versions of "V." in circulation. This was due to the fact that Pynchon's final modifications were made after the first edition was printed and thus were only implemented in the British, or Jonathan Cape, edition and the Bantam paperback. The fact was forgotten soon after in the U.S., so most US editions, including the newly released eBook, follow the first printing and are therefore unauthorized versions of the text, while the British editions, which follow the first edition printed by Jonathan Cape, contain Pynchon's final revisions.


title: Head and neck cancer

text: Head and neck cancer develops from tissues in the lip and oral cavity (mouth), larynx (throat), salivary glands, nose, sinuses or the skin of the face. The most common types of head and neck cancers occur in the lip, mouth, and larynx. Symptoms predominantly include a sore that does not heal or a change in the voice. Some may experience a sore throat that does not go away. In those with advanced disease, there may be unusual bleeding, facial pain, numbness or swelling, and visible lumps on the outside of the neck or oral cavity. Given the location of these cancers, trouble breathing may also be present.


title: Head and neck cancer

text: The majority of head and neck cancer is caused by the use of alcohol or tobacco, including smokeless tobacco, with increasing cases linked to the human papillomavirus (HPV). Other risk factors include Epstein-Barr virus, betel quid, radiation exposure, certain workplace exposures. About 90% are pathologically classified as squamous cell cancers. The diagnosis is confirmed by tissue biopsy. The degree of surrounding tissue invasion and distant spread may be determined by medical imaging and blood tests.


title: Head and neck cancer

text: Not using tobacco or alcohol can reduce the risk for head and neck cancer. The HPV vaccine may reduce the lifetime risk of oral cancer if taken prior to the onset of sexual activity, but confirmation will likely not be known until around 2060. This is because oropharyngeal cancer typical presents in the 4th – 6th decade of life, and this is a relatively new vaccine. While screening in the general population does not appear to be useful, screening high risk groups by examination of the throat might be useful. Head and neck cancer often is curable if it is diagnosed early; however, outcomes are typically poor if it is diagnosed late. Treatment may include a combination of surgery, radiation therapy, chemotherapy, and targeted therapy. Previous diagnosis and treatment of one head and neck cancer confers higher risk of developing a second head and neck cancer or recurrence.


title: Head and neck cancer

text: Globally, head and neck cancer accounts for 650,000 new cases of cancer and 330,000 deaths annually on average. In 2018, it was the seventh most common cancer worldwide with 890,000 new cases documented and 450,000 dying from the disease. In the United States, head and neck cancer makes up 3% of all cancer cases (averaging 53,000 new diagnoses per year) and 1.5% of cancer deaths. The 2017 worldwide figure cites head and neck cancers as representing 5.3% of all cancers (not including non-melanoma skin cancers). Notably, head and neck cancer secondary to chronic alcohol or tobacco use has been steadily declining as less of the population chronically smokes tobacco. However, HPV-associated oropharyngeal cancer is rising, particularly in younger people in westernized nations, which is thought to be reflective of changes in oral sexual practices, specifically with regard to the number of oral sexual partners. This increase since the 1970s has mostly affected wealthier nations and male populations. This is due to evidence suggesting that transmission rates of HPV from women to men are higher than men to women, as women often have a higher immune response to infection.


title: Head and neck cancer

text: The usual age at diagnosis is between 55 and 65 years old. The average 5-year survival following diagnosis in the developed world is 42–64%.


title: Head and neck cancer

text: Symptoms predominantly include a sore of the face or oral cavity that does not heal, trouble swallowing, or a change in the voice. In those with advanced disease, there may be unusual bleeding, facial pain, numbness or swelling, and visible lumps on the outside of the neck or oral cavity. Head and neck cancer often begins with benign signs and symptoms of disease, like an enlarged lymph node on the outside of the neck, a hoarse-sounding voice or progressive worsening cough or sore throat. In the case of head and neck cancer, these symptoms will be notably persistent and become chronic. There may be a lump or a sore in the throat or neck that does not heal or go away. There may be difficult or painful swallowing. Speaking may become difficult. There may also be a persistent earache.


title: Head and neck cancer

text: Other symptoms can include: a lump in the lip, mouth or gums, ulcers or mouth sores that do not heal, bleeding from the mouth or numbness, bad breath, discolored patches that persist in the mouth, a sore tongue, and slurring of speech if the cancer is affecting the tongue. There may also be congested sinuses, weight loss, and some numbness or paralysis of facial muscles.


title: Head and neck cancer

text: Squamous cell cancers are common in areas of the mouth, including the inner lip, tongue, floor of mouth, gums, and hard palate. Cancers of the mouth are strongly associated with tobacco use, especially use of chewing tobacco or dipping tobacco, as well as heavy alcohol use. Cancers of this region, particularly the tongue, are more frequently treated with surgery than are other head and neck cancers. Lip and oral cavity cancers are the most typically encountered type of head and neck cancers.


title: Head and neck cancer

text: The defect is typically covered/improved by using another part of the body and/or skin grafts and/or wearing a prosthesis.


title: Head and neck cancer

text: Paranasal sinus and nasal cavity cancer affects the nasal cavity and the paranasal sinuses. Most of these cancers are squamous cell carcinomas.


title: Head and neck cancer

text: Nasopharyngeal cancer arises in the nasopharynx, the region in which the nasal cavities and the Eustachian tubes connect with the upper part of the throat. While some nasopharyngeal cancers are biologically similar to the common head and neck squamous cell carcinomas (HNSCCs), "poorly differentiated" nasopharyngeal carcinoma is lymphoepithelioma, which is distinct in its epidemiology, biology, clinical behavior, and treatment, and is treated as a separate disease by many experts.


title: Head and neck cancer

text: Most oropharyngeal cancers are squamous cell carcinomas that begin in the oropharynx (throat), the middle part of the throat that includes the soft palate, the base of the tongue, and the tonsils. Squamous cell cancers of the tonsils are more strongly associated with human papillomavirus infection than are cancers of other regions of the head and neck. HPV-positive oropharyngeal cancer generally has a better outcomes than HPV-negative disease with a 54% better survival, but this advantage for HPV associated cancer applies only to oropharyngeal cancers.


title: Head and neck cancer

text: People with oropharyngeal carcinomas are at high risk of developing second primary head and neck cancer.


title: Head and neck cancer

text: The hypopharynx includes the pyriform sinuses, the posterior pharyngeal wall, and the postcricoid area. Tumors of the hypopharynx frequently have an advanced stage at diagnosis, and have the most adverse prognoses of pharyngeal tumors. They tend to metastasize early due to the extensive lymphatic network around the larynx.


title: Head and neck cancer

text: Laryngeal cancer begins in the larynx or "voice box", and is the second most common type of head and neck cancer encountered. Cancer may occur on the vocal folds themselves ("glottic" cancer), or on tissues above and below the true cords ("supraglottic" and "subglottic" cancers respectively). Laryngeal cancer is strongly associated with tobacco smoking.


title: Head and neck cancer

text: Surgery can include laser excision of small vocal cord lesions, partial laryngectomy (removal of part of the larynx) or total laryngectomy (removal of the whole larynx). If the whole larynx has been removed, the person is left with a permanent tracheostomy. Voice rehabilitation in such patients can be achieved through three important ways – esophageal speech, tracheoesophageal puncture, or electrolarynx. One would likely require the help of intensive teaching and speech therapy and/or an electronic device.


title: Head and neck cancer

text: Most tumors of the salivary glands differ from the common squamous cell carcinomas of the head and neck in cause, histopathology, clinical presentation, and therapy. Other uncommon tumors arising in the head and neck include teratomas, adenocarcinomas, adenoid cystic carcinomas, and mucoepidermoid carcinomas. Rarer still are melanomas and lymphomas of the upper aerodigestive tract.


title: Head and neck cancer

text: Tobacco smoking is one of the main risk factors for head and neck cancer. A major carcinogenic compound in tobacco smoke is acrylonitrile. Acrylonitrile appears to indirectly cause DNA damage by increasing oxidative stress, leading to increased levels of 8-oxo-2'-deoxyguanosine (8-oxo-dG) and formamidopyrimidine in DNA. (see image). Both 8-oxo-dG and formamidopyrimidine are mutagenic. DNA glycosylase NEIL1 prevents mutagenesis by 8-oxo-dG and removes formamidopyrimidines from DNA.


title: Head and neck cancer

text: However, cigarette smokers have a lifetime increased risk for head and neck cancers that is 5- to 25-fold increased over the general population.


title: Head and neck cancer

text: The ex-smoker's risk for developing a head and neck cancer begins to approach the risk in the general population 15 years after smoking cessation. The high prevalence of tobacco and alcohol use worldwide and the high association of these cancers with these substances makes them ideal targets for enhanced cancer prevention.


title: Head and neck cancer

text: Smokeless tobacco is a cause of oral cancer and oropharyngeal cancer. Smokeless tobacco (including products where tobacco is chewed) is associated with a risk of developing head and neck cancers; this link has been established in the United States as well as in East Asian countries.Cigar smoking is also an important risk factor for oral cancer. It should also be noted that the use of electronic cigarettes may also lead to the development of head and neck cancers due to the substances like propylene glycol, glycerol, nitrosamines and metals contained there in; which can cause damage to airways. This area of study requires more research to prove correlation and/or causation, however.


title: Head and neck cancer

text: Other environmental carcinogens suspected of being potential causes of head and neck cancer include occupational exposures such as nickel ore refining, exposure to textile fibers, and woodworking. Use of marijuana, especially when younger, has been linked to an increase in squamous-cell carcinoma cases in at least one study, while other studies suggest use is not shown to be associated with oral squamous cell carcinoma, or associated with decreased squamous cell carcinoma.


title: Head and neck cancer

text: Excessive consumption of eggs, processed meats, and red meat were associated with increased rates of cancer of the head and neck in one study, while consumption of raw and cooked vegetables seemed to be protective.


title: Head and neck cancer

text: Vitamin E was not found to prevent the development of leukoplakia, the white plaques that are the precursor for carcinomas of the mucosal surfaces, in adult smokers.


title: Head and neck cancer

text: Another study examined a combination of Vitamin E and beta carotene in smokers with early-stage cancer of the oropharynx, and found a worse prognosis in the vitamin users.


title: Head and neck cancer

text: Some head and neck cancers are caused by human papillomavirus (HPV). In particular, HPV16 is a causal factor for some head and neck squamous-cell carcinomas (HNSCCs). Approximately 15–25% of HNSCC contain genomic DNA from HPV, and the association varies based on the site of the tumor, especially HPV-positive oropharyngeal cancer, with highest distribution in the tonsils, where


title: Head and neck cancer

text: HPV DNA is found in (45 to 67%) of the cases, less often in the hypopharynx (13–25%), and least often in the oral cavity (12–18%) and larynx (3–7%).


title: Head and neck cancer

text: Some experts estimate that while up to 50% of cancers of the tonsil may be infected with HPV, only 50% of these are likely to be caused by HPV (as opposed to the usual tobacco and alcohol causes). The role of HPV in the remaining 25–30% is not yet clear. Oral sex is not risk free and results in a significant proportion of HPV-related head and neck cancer.


title: Head and neck cancer

text: Induction of cancer can be associated for the expression of viral oncoproteins, the most important E6 and E7, or other mechanisms many of them run by the integration such as the generation of altered transcripts, disruption of tumor suppressors, high levels of DNA amplifications, interchromosomial rearrangements, or changes in DNA methylation patterns, the latter being able to find even when the virus is identified in episomes. E6 sequesters p53 to promote p53 degradation while E7 inhibits pRb. p53 prevents cell growth when DNA is damaged by activating apoptosis and p21, a kinase that blocks the formation of cyclin D / Cdk4 avoiding pRb phosphorylation and thereby prevents release of E2F is a transcription factor required for activation of genes involved in cell proliferation. pRb remains bound to E2F while this action phosphorylated preventing activation of proliferation. Therefore, E6 and E7 act synergistically in triggering cell cycle progression and therefore uncontrolled proliferation by inactivating the p53 and Rb tumor suppressors.


title: Head and neck cancer

text: Viral integration tends to occur in or near oncogenes or tumor suppressor genes and it is for this reason that the integration of the virus can greatly contribute to the development of tumor characteristics.


title: Head and neck cancer

text: Epstein–Barr virus (EBV) infection is associated with nasopharyngeal cancer. Nasopharyngeal cancer occurs endemically in some countries of the Mediterranean and Asia, where EBV antibody titers can be measured to screen high-risk populations. Nasopharyngeal cancer has also been associated with consumption of salted fish, which may contain high levels of nitrites.


title: Head and neck cancer

text: The presence of acid reflux disease (gastroesophageal reflux disease [GERD]) or larynx reflux disease can also be a major factor. Stomach acids that flow up through the esophagus can damage its lining and raise susceptibility to throat cancer.


title: Head and neck cancer

text: Patients after hematopoietic stem cell transplantation (HSCT) are at a higher risk for oral squamous cell carcinoma. Post-HSCT oral cancer may have more aggressive behavior with poorer prognosis, when compared to oral cancer in non-HSCT patients. This effect is supposed to be owing to the continuous lifelong immune suppression and chronic oral graft-versus-host disease.


title: Head and neck cancer

text: There are several risk factors for developing throat cancer. These include smoking or chewing tobacco or other things, such as gutkha, or paan, heavy alcohol consumption, poor diet resulting in vitamin deficiencies (worse if this is caused by heavy alcohol intake), weakened immune system, asbestos exposure, prolonged exposure to wood dust or paint fumes, exposure to petroleum industry chemicals, and being over the age of 55 years. Other risk factors include the appearance of white patches or spots in the mouth, known as leukoplakia, which in about of cases develops into cancer, and breathing or inhaling silica from cutting concrete, stone or cinder-blocks, especially in enclosed areas such as a warehouse, garage or basement.


title: Head and neck cancer

text: A person usually presents to the physician complaining of The person will typically undergo a needle biopsy of this lesion, and a histopathologic information is available, a multidisciplinary discussion of the optimal treatment strategy will be undertaken between the radiation oncologist, surgical oncologist, and medical oncologist. Most (90%) cancers of the head and neck are squamous cell-derived termed as "head-and-neck squamous-cell carcinomas".


title: Head and neck cancer

text: Throat cancers are classified according to their histology or cell structure, and are commonly referred to by their location in the oral cavity and neck. This is because where the cancer appears in the throat affects the prognosis – some throat cancers are more aggressive than others depending upon their location. The stage at which the cancer is diagnosed is also a critical factor in the prognosis of throat cancer. Treatment guidelines recommend routine testing for the presence of HPV for all oropharyngeal squamous cell carcinoma tumours.


title: Head and neck cancer

text: Squamous-cell carcinoma is a cancer of the squamous cell – a kind of epithelial cell found in both the skin and mucous membranes. It accounts for over 90% of all head and neck cancers, including more than 90% of throat cancer. Squamous cell carcinoma is most likely to appear in males over 40 years of age with a history of heavy alcohol use coupled with smoking.


title: Head and neck cancer

text: The tumor marker Cyfra 21-1 may be useful in diagnosing squamous cell carcinoma of the head/neck (SCCHN).


title: Head and neck cancer

text: Adenocarcinoma is a cancer of epithelial tissue that has glandular characteristics. Several head and neck cancers are adenocarcinomas (either of intestinal or non-intestinal cell-type).


title: Head and neck cancer

text: Avoidance of recognised risk factors (as described above) is the single most effective form of prevention. Regular dental examinations may identify pre-cancerous lesions in the oral cavity.


title: Head and neck cancer

text: When diagnosed early, oral, head and neck cancers can be treated more easily and the chances of survival increase tremendously. As of 2017 it was not known if existing HPV vaccines can help prevent head and neck cancer.


title: Head and neck cancer

text: Improvements in diagnosis and local management, as well as targeted therapy, have led to improvements in quality of life and survival for people with head and neck cancer.


title: Head and neck cancer

text: After a histologic diagnosis has been established and tumor extent determined, the selection of appropriate treatment for a specific cancer depends on a complex array of variables, including tumor site, relative morbidity of various treatment options, concomitant health problems, social and logistic factors, previous primary tumors, and the person's preference. Treatment planning generally requires a multidisciplinary approach involving specialist surgeons and medical and radiation oncologists.


title: Head and neck cancer

text: Surgical resection and radiation therapy are the mainstays of treatment for most head and neck cancers and remain the standard of care in most cases. For small primary cancers without regional metastases (stage I or II), wide surgical excision alone or curative radiation therapy alone is used. More extensive primary tumors, or those with regional metastases (stage III or IV), planned combinations of pre- or postoperative radiation and complete surgical excision are generally used. More recently, as historical survival and control rates are recognized as less than satisfactory, there has been an emphasis on the use of various induction or concomitant chemotherapy regimens.


title: Head and neck cancer

text: Surgery as a treatment is frequently used in most types of head and neck cancer. Usually the goal is to remove the cancerous cells entirely. This can be particularly tricky if the cancer is near the larynx and can result in the person being unable to speak. Surgery is also commonly used to resect (remove) some or all of the cervical lymph nodes to prevent further spread of the disease.


title: Head and neck cancer

text: CO laser surgery is also another form of treatment. Transoral laser microsurgery allows surgeons to remove tumors from the voice box with no external incisions. It also allows access to tumors that are not reachable with robotic surgery. During the surgery, surgeon and pathologist work together to assess the adequacy of excision ("margin status"), minimizing the amount of normal tissue removed or damaged. This technique helps give the person as much speech and swallowing function as possible after surgery.


title: Head and neck cancer

text: Radiation therapy is the most common form of treatment. There are different forms of radiation therapy, including 3D conformal radiation therapy, intensity-modulated radiation therapy, particle beam therapy and brachytherapy, which are commonly used in the treatments of cancers of the head and neck. Most people with head and neck cancer who are treated in the United States and Europe are treated with intensity-modulated radiation therapy using high energy photons. At higher doses, head and neck radiation is associated with thyroid dysfunction and pituitary axis dysfunction. Radiation therapy of head and neck cancers can also cause acute skin reactions of varying levels of severity, which can be treated and managed with topically applied creams or specialist films.


title: Head and neck cancer

text: Chemotherapy in throat cancer is not generally used to "cure" the cancer as such. Instead, it is used to provide an inhospitable environment for metastases so that they will not establish in other parts of the body. Typical chemotherapy agents are a combination of paclitaxel and carboplatin. Cetuximab is also used in the treatment of throat cancer.


title: Head and neck cancer

text: Docetaxel-based chemotherapy has shown a very good response in locally advanced head and neck cancer. Docetaxel is the only taxane approved by US FDA for head and neck cancer, in combination with cisplatin and fluorouracil for the induction treatment of inoperable, locally advanced squamous cell carcinoma of the head and neck.


title: Head and neck cancer

text: While not specifically a chemotherapy, amifostine is often administered intravenously by a chemotherapy clinic prior to IMRT radiotherapy sessions. Amifostine protects the gums and salivary glands from the effects of radiation.


title: Head and neck cancer

text: Photodynamic therapy may have promise in treating mucosal dysplasia and small head and neck tumors. Amphinex is giving good results in early clinical trials for treatment of advanced head and neck cancer.


title: Head and neck cancer

text: Targeted therapy, according to the National Cancer Institute, is "a type of treatment that uses drugs or other substances, such as monoclonal antibodies, to identify and attack specific cancer cells without harming normal cells." Some targeted therapy used in squamous cell cancers of the head and neck include cetuximab, bevacizumab and erlotinib.


title: Head and neck cancer

text: The best quality data are available for cetuximab since the 2006 publication of a randomized clinical trial comparing radiation treatment plus cetuximab versus radiation treatment alone. This study found that concurrent cetuximab and radiotherapy improves survival and locoregional disease control compared to radiotherapy alone, without a substantial increase in side effects, as would be expected with the concurrent chemoradiotherapy, which is the current gold standard treatment for advanced head and neck cancer. Whilst this study is of pivotal significance, interpretation is difficult since cetuximab-radiotherapy was not directly compared to chemoradiotherapy. The results of ongoing studies to clarify the role of cetuximab in this disease are awaited with interest.


title: Head and neck cancer

text: Another study evaluated the impact of adding cetuximab to conventional chemotherapy (cisplatin) versus cisplatin alone. This study found no improvement in survival or disease-free survival with the addition of cetuximab to the conventional chemotherapy.


title: Head and neck cancer

text: However, another study which completed in March 2007 found that there was an improvement in survival.


title: Head and neck cancer

text: A 2010 review concluded that the combination of cetuximab and platin/5-fluorouracil should be considered the current standard first-line regimen.


title: Head and neck cancer

text: Gendicine is a gene therapy that employs an adenovirus to deliver the tumor suppressor gene p53 to cells. It was approved in China in 2003 for the treatment of head and neck squamous cell carcinoma.


title: Head and neck cancer

text: The mutational profile of HPV+ and HPV- head and neck cancer has been reported, further demonstrating that they are fundamentally distinct diseases.


title: Head and neck cancer

text: Immunotherapy is a type of treatment that activates the immune system to fight cancer. One type of immunotherapy, immune checkpoint blockade, binds to and blocks inhibitory signals on immune cells to release their anti-cancer activities.


title: Head and neck cancer

text: In 2016, the FDA granted accelerated approval to pembrolizumab for the treatment of people with recurrent or metastatic HNSCC with disease progression on or after platinum-containing chemotherapy. Later that year, the FDA approved nivolumab for the treatment of recurrent or metastatic HNSCC with disease progression on or after platinum-based chemotherapy. In 2019, the FDA approved pembrolizumab for the first-line treatment of metastatic or unresectable recurrent HNSCC.


title: Head and neck cancer

text: Depending on the treatment used, people with head and neck cancer may experience the following symptoms and treatment side effects:


title: Head and neck cancer

text: Programs to support the emotional and social well-being of people who have been diagnosed with head and neck cancer may be offered. There is no clear evidence on the effectiveness of these interventions or any particular type of psychosocial program or length of time that is the most helpful for those with head and neck cancer.


title: Head and neck cancer

text: Although early-stage head and neck cancers (especially laryngeal and oral cavity) have high cure rates, up to 50% of people with head and neck cancer present with advanced disease.


title: Head and neck cancer

text: Cure rates decrease in locally advanced cases, whose probability of cure is inversely related to tumor size and even more so to the extent of regional node involvement. HPV-associated oropharyngeal cancer has been shown to respond better to chemoradiation and, subsequently, a better prognosis, compared to non-associated HPV head and neck cancer.


title: Head and neck cancer

text: Consensus panels in America (AJCC) and Europe (UICC) have established staging systems for head and neck squamous-cell cancers. These staging systems attempt to standardize clinical trial criteria for research studies, and attempt to define prognostic categories of disease. Squamous cell cancers of the head and neck are staged according to the TNM classification system, where T is the size and configuration of the tumor, N is the presence or absence of lymph node metastases, and M is the presence or absence of distant metastases. The T, N, and M characteristics are combined to produce a "stage" of the cancer, from I to IVB.


title: Head and neck cancer

text: Survival advantages provided by new treatment modalities have been undermined by the significant percentage of people cured of head and neck squamous cell carcinoma (HNSCC) who subsequently develop second primary tumors. The incidence of second primary tumors ranges in studies from 9%


title: Head and neck cancer

text: at 20 years. Second primary tumors are the major threat to long-term survival after successful therapy of early-stage HNSCC. Their high incidence results from the same carcinogenic exposure responsible for the initial primary process, called field cancerization.


title: Head and neck cancer

text: Many people with head and neck cancer are also not able to eat sufficiently. A tumor may impair a person's ability to swallow and eat, and throat cancer may affect the digestive system. The difficulty in swallowing can lead to a person to choke on their food in the early stages of digestion and interfere with the food's smooth travels down into the esophagus and beyond.


title: Head and neck cancer

text: The treatments for throat cancer can also be harmful to the digestive system as well as other body systems. Radiation therapy can lead to nausea and vomiting, which can deprive a body of vital fluids (although these may be obtained through intravenous fluids if necessary). Frequent vomiting can lead to an electrolyte imbalance which has serious consequences for the proper functioning of the heart. Frequent vomiting can also upset the balance of stomach acids which has a negative impact on the digestive system, especially the lining of the stomach and esophagus.


title: Head and neck cancer

text: Enteral feeding, a method that adds nutrients directly into a person's stomach using a nasogastric feeding tube or a gastrostomy tube, may be necessary for some people. Further research is required to determine the most effective method of enteral feeding to ensure that people undergoing radiotherapy or chemoradiation treatment are able to stay nourished during their treatment.


title: Head and neck cancer

text: In the cases of some throat cancers, the air passages in the mouth and behind the nose may become blocked from lumps or the swelling from the open sores. If the throat cancer is near the bottom of the throat, it has a high likelihood of spreading to the lungs and interfering with the person's ability to breathe; this is even more likely if the person is a smoker, because they are highly susceptible to lung cancer.


title: Head and neck cancer

text: Cancer in the head or neck may impact a person's mental well-being and can sometimes lead to social isolation. This largely results from decreased ability or inability to eat, speak or effectively communicate. Physical appearance is often altered by both the cancer itself or as a consequence of treatment side effects. Psychological distress may occur and feelings such as uncertainty and fear may arise. Some people may also have a changed physical appearance, differences in swallowing or breathing, and residual pain to manage.


title: Head and neck cancer

text: Multiple studies have shown caregivers for head and neck cancer patients show higher rates of distress and poorer mental health compared to both the general population as well as those caring for non-head-and-neck cancer patients. The high symptom burden patients' experience necessitate complex caregiver roles, often requiring hospital staff training, which caregivers can find distressing when asked to do so for the first time. It is becoming increasingly apparent caregivers (most often spouses, children or close family members) might not be adequately informed about, nor prepared or trained for the tasks and roles he/she will encounter during the treatment and recovery phase for this unique patient population, which span both technical and emotional support. Of note, caregivers of patient's who report lower quality of life, demonstrate increased burden and fatigue that extents beyond the treatment phase.


title: Head and neck cancer

text: Examples of technically difficult caregiver duties include: tube feeding, oral suctioning, wound maintenance, medication delivery safe for tube feeding, and trouble shooting at home medical equipment. If the cancer affect the mouth or larynx, caregivers must also find a way to effectively communicate amongst themselves and with their healthcare team. This is in addition to providing emotional support for the person undergoing cancer therapy.


title: Head and neck cancer

text: Like any cancer, metastasization affects many areas of the body, as the cancer spreads from cell to cell and organ to organ. For example, if it spreads to the bone marrow, it will prevent the body from producing enough red blood cells and affects the proper functioning of the white blood cells and the body's immune system; spreading to the circulatory system will prevent oxygen from being transported to all the cells of the body; and throat cancer can throw the nervous system into chaos, making it unable to properly regulate and control the body.


title: Head and neck cancer

text: The number of new cases of head and neck cancers in the United States was 40,490 in 2006, accounting for about 3% of adult malignancies. A total of 11,170 people died of their disease in 2006. The worldwide incidence exceeds half a million cases annually. In North America and Europe, the tumors usually arise from the oral cavity, oropharynx, or larynx, whereas nasopharyngeal cancer is more common in the Mediterranean countries and in the Far East. In Southeast China and Taiwan, head and neck cancer, specifically nasopharyngeal cancer, is the most-common cause of death in young men.


title: Ascaris

text: Ascaris is a genus of parasitic nematode worms known as the "small intestinal roundworms", which is a type of parasitic worm. One species, "Ascaris lumbricoides", affects humans and causes the disease ascariasis. Another species, "Ascaris suum", typically infects pigs. "Parascaris equorum", the equine roundworm, is also commonly called an "ascarid".


title: Ascaris

text: Their eggs are deposited in feces and soil. Plants with the eggs on them infect any organism that consumes them. "A. lumbricoides" is the largest intestinal roundworm and is the most common helminth infection of humans worldwide. Infestation can cause morbidity by compromising nutritional status, affecting cognitive processes, inducing tissue reactions such as granuloma to larval stages, and by causing intestinal obstruction, which can be fatal.


title: Ascaris

text: The body is long, cylindrical, and fusiform (pointed at both the ends). The body wall is composed of cuticle, epidermis and musculature. There is a pseudocoelom. Respiration is by simple diffusion. The nervous system consists of a nerve ring and many longitudinal nerve cords. Reproduction is exclusively sexual, and males are usually shorter than females.


title: Ascaris

text: As part of the parasite defense strategy, "Ascaris" roundworms secrete a series of inhibitors to target digestive and immune-related host proteases, which include pepsin, trypsin, chymotrypsin/elastase, cathepsins, and metallocarboxypeptidases (MCPs).


title: Ascaris

text: "Ascaris" species inhibit MCPs by releasing an enzyme known as "Ascaris" carboxypeptidase inhibitor (ACI). This enzyme binds to the active site of MCP and blocks the cleavage of its own proteins by the host MCP. Similarly, they inhibit trypsin by releasing the protein Ascaris Trypsin Inhibitor (pdb 1ATA).


title: Ascaris

text: "Ascaris" has been present in humans for at least several thousand years, as evidenced by "Ascaris" eggs found in paleofeces and in the intestines of mummified humans.


title: Ascaris

text: "A. lumbricoides" was originally called "Lumbricus teres" and was first described in detail by Edward Tyson in 1683. The genus "Ascaris" was originally described as the genus for "Ascaris lumbricoides" by Carl Linnaeus in 1758. The morphologically similar "Ascaris suum" was described from pigs by Johann August Ephraim Goeze in 1782.


title: Sushil Kumar

text: Sushil Kumar Solanki (born 26 May 1983) is a former Indian wrestler. He carried the Indian flag at the opening ceremony of 2012 London Olympics. His 2008 Olympic medal was second for India in wrestling, and the first since Khashaba Dadasaheb Jadhav's bronze medal at the 1952 Summer Olympics. In July 2009, he received the Major Dhyan Chand Khel Ratna – India's highest honour for sportspersons. On 3 October 2010, Kumar handed the Queen's Baton to Prince Charles in the Queen's Baton Relay for the 2010 Commonwealth Games Opening Ceremony. Sushil won the gold medal in the 74 kg division at the 2014 Commonwealth Games.


title: Sushil Kumar

text: Kumar started training in pehlwani at the Chhatrasal Stadium's "akhada" at the age of 14. He was trained at the "akhada" by Yashvir and Ramphal, later by Arjuna awardee Satpal and then at the Indian Railways camp by Gyan Singh and Rajkumar Baisla Gurjar.


title: Sushil Kumar

text: After switching to freestyle wrestling Kumar's first success came at the World Cadet Games in 1998 where he won the gold medal in his weight category, followed by a gold at the Asian Junior Wrestling Championship in 2000.


title: Sushil Kumar

text: Moving out of the junior competitions, in 2003 Kumar won the bronze medal at the Asian Wrestling Championships and a gold at the Commonwealth Wrestling Championships. Kumar placed fourth at the 2003 World Championships, but this went largely unnoticed by the Indian media as he fared badly in the 2004 Olympic Games in Athens, placing 14th in the 60 kg weight class. He won gold medals at the Commonwealth wrestling championships in 2005 and 2007. He placed seventh in the 2007 World Championships and won a bronze medal at the 2008 Olympic Games in Beijing. He won a silver medal at the 2012 Summer Olympics, becoming the first person to win two Olympic medals for independent India.


title: Sushil Kumar

text: Kumar was awarded the Arjuna Award in 2006 and a coveted Padma Shree by the Indian Government in 2011.


title: Sushil Kumar

text: Kumar lost to Andriy Stadnik in the first round of the 66 kg freestyle wrestling event, leaving his medal hopes hinging on the repechage. He defeated Doug Schwab in the first repechage round and Albert Batyrov in the second round. In the bronze medal match on 20 August 2008, Kumar beat Leonid Spiridonov 3:1. Kumar disclosed that he had no masseur during the three bouts he won within a span of 70 minutes to take the bronze. The team manager Kartar Singh who is a former Asian Games medallist acted as the masseur for him.


title: Sushil Kumar

text: At the 2010 World Wrestling Championships Kumar became the first Indian to win a world title in wrestling. He beat the local favourite Alan Gogaev of Russia 3–1 in the finals in the 66 kg category.


title: Sushil Kumar

text: Kumar won gold medal at the 2010 Commonwealth Games held in Delhi on 10 October 2010. He beat Heinrich Barnes 7–0 in the finals in the 66 kg freestyle wrestling category. The bout was stopped by the referee in the second round. Earlier, in the semifinals, Kumar defeated Famara Jarjou 3–0 within 9 seconds. In the quarterfinals, Kumar defeated Muhammad Salman 10–0 in 46 seconds.


title: Sushil Kumar

text: Earlier, he had entered the final amid some controversy by beating Kazakhastan's Akzhurek Tanatarov in the semifinal. The Kazakh athlete claimed that Kumar had bitten his ear, which was denied by the latter.


title: Sushil Kumar

text: Kumar was the Olympic flag bearer for India at the opening ceremony. This win made him the first Indian to win 2 individual Olympic Medals since India's Independence.


title: Sushil Kumar

text: Kumar defeated Qamar Abbas in the 74 kg final to win the gold medal at the 2014 Commonwealth Games in Glasgow, Scotland. He won in 107 seconds by fall.