In audiology, tympanometry is sometimes referred to as immittance testing. Tympanometry is especially effective when both the impedance and admittance of the inner ear are accounted for. Immittance allows for the analysis of both, and therefore is crucial to multiple-component, multiple-frequency tympanometry. Clinically, few cases require the use of this technique for accurate diagnosis; but for the fewer than 20% of cases which do require it, the technique is a necessity. Multiple-component, multiple-frequency tympanometry is invaluable for the differential diagnosis of fixation of the lateral ossicular chain from fixation of the stapes, profound mixed hearing losses, clinical otosclerosis from disruption of the ossicular chain, hypermobility of the incudostapedial joint, and congenital ossicular fixation in children.