10.14639/0392-100X-N1640
text/xml
1827-675X
1640
en
Thomas P. Nikolopoulos
http://creativecommons.org/licenses/by-nc-nd/4.0
ACTA Otorhinolaryngologica Italica
independency
Introducing a modified algorithm for enhanced operator independency in auditory steady-state responses (ASSRs) testing
Text.Serial.Journal
https://www.actaitalica.it/
41
Letters to the Editor-in-Chief
2023-10-18
2021-04-26
2021-12-22
2023-10-18
572-573
1
Thomas P. Nikolopoulos
2021
10.14639/0392-100X-N1640
572
ENT Dept., Attikon University Hospital, Athens, Greece
1827-675X
independency
573
Introducing a modified algorithm for enhanced operator independency in auditory steady-state responses (ASSRs) testing
https://www.actaitalica.it/article/download/1640/705
41
ACTA OTORHINOLARYNGOLOGICA ITALICA 2021;41:572-573; doi: 10.14639/0392-100X-N1640




Letter to the Editor


Introducing a modified algorithm for enhanced
operator independency in auditory steady-state
responses (ASSR) testing
Presentazione di un algoritmo modificato per una maggiore indipendenza
dell’operatore nei test delle risposte uditive allo steady-state (ASSR)
Petros V. Vlastarakos1*, John Plioutas2*, Alexandros Delidis2, Thomas P. Nikolopoulos2
1
    ENT Dept., MITERA Infirmary, Athens, Greece; 2 ENT Dept., Attikon University Hospital, Athens, Greece
*
    P.V. Vlastarakos and J. Plioutas contributed equally to this work.


KEY WORDS: ASSR, hearing, algorithm, reliability, independency
PAROLE CHIAVE: ASSR, udito, algoritmo, affidabilità, indipendenza


Dear Editor,
Auditory steady-state responses (ASSR) are used to objectively assess the
hearing thresholds of a given individual. Their value stems from reliably indi-
cating the actual hearing levels (HLs) in four main frequencies (500 Hz, 1000
Hz, 2000 Hz, 4000 Hz), by obtaining a valid estimated audiogram through the
use of statistical measures 1. Since mathematical prerequisites should be ful-            Received: April 26, 2021
                                                                                          Accepted: June 14, 2021
filled in order for brainstem responses to be transformed into estimated HLs,
                                                                                          Published online: November 26, 2021
ASSR are largely considered to be operator-independent.
Nevertheless, the “extended-time” value represents an operator-dependent pa-              Correspondence
rameter, which may relativise the independence of ASSR testing on the basis               Petros V. Vlastarakos
                                                                                          ENT Dept., MITERA Infirmary, Athens, Greece
of the operator’s experience or even wish. Indeed, the examination time is                E-mail: pevlast@hotmail.com
set to six minutes per examined frequency and HL in each ear. Whenever the
stimulus curve reaches 100% certainty, it turns green (positive outcome) and              Funding
the operator lowers the stimulus by 10 dB. If the curve remains under 100%                None.
by the end of the examination time, the outcome is negative, yet the examiner
                                                                                          Conflict of interest
may choose to extend the test by one minute, assuming that a positive outcome             The Authors declare no conflict of interest.
is likely to occur, and perform this time-extension repeatedly. This introduces
an obvious intervention to the operator-independency of the test, with poten-               How to cite this article: Vlastarakos PV, Pliou-
tial impact on the results obtained.                                                        tas J, Delidis A, et al. Introducing a modified
We propose a standardised operator-independent protocol regarding the “ex-                  algorithm for enhanced operator independency
                                                                                            in auditory steady-state responses (ASSR) test-
tended-time” value, in which, whenever the curve of the stimulus reaches 80%                ing. Acta Otorhinolaryngol Ital 2021;41:572-573.
certainty, the testing time is extended by one minute once, and whenever the                https://doi.org/10.14639/0392-100X-N1640
curve of the stimulus reaches 90% certainty (or above), the testing time is ex-
                                                                                          © Società Italiana di Otorinolaringoiatria
tended by one minute, for as long as the curve remains above 90%, and stops,              e Chirurgia Cervico-Facciale
when the curve reaches 100% certainty, or drops below 90%. The proposed
protocol was tested in a cohort of 47 hearing-impaired individuals 2 (age-range                          OPEN ACCESS
14-85 years old 3) in a soundproof chamber, with 40 Hz stimulus-rate CE-                  This is an open access article distributed in accordance with
                                                                                          the CC-BY-NC-ND (Creative Commons Attribution-Non-
chirp® sounds given through insert phones. The correlation between pure-tone              Commercial-NoDerivatives 4.0 International) license. The
audiometry (PTA) and ASSR measurements was performed using the intra-                     article can be used by giving appropriate credit and mentio-
                                                                                          ning the license, but only for non-commercial purposes and
class correlation coefficient (ICC 1,1) (Tab. I). Statistical importance was ac-          only in the original version. For further information: https://
cepted at the 0.05 level of significance.                                                 creativecommons.org/licenses/by-nc-nd/4.0/deed.en




572
                                                                                                                                    ASSR testing and operator-independency




Table I. Correlation of ASSR estimates to actual PTA measurements.
 Ear                                        Frequency                                  *
                                                                                           PTA-ASSR                    *
                                                                                                                           PTA-ASSRWET                  p-value
 Right                                               500 Hz                        0.922 (0.86-0.96)                 0.875 (0.78-0.93)                   0.075
                                                     1000 Hz                       0.901 (0.83-0.95)                 0.829 (0.71-0.90)                   0.021
                                                     2000 Hz                       0.904 (0.83-0.95)                 0.845 (0.74-0.91)                   0.049
                                                     4000 Hz                       0.917 (0.85-0.95)                 0.895 (0.82-0.94)                   0.384
 Left                                                 500 Hz                       0.901 (0.83-0.94)                 0.856 (0.75-0.92)                   0.127
                                                     1000 Hz                       0.914 (0.85-0.95)                 0.823 (0.70-0.90)                   0.003
                                                     2000 Hz                       0.943 (0.90-0.97)                 0.863 (0.77-0.92)                   0.001
                                                     4000 Hz                       0.890 (0.81-0.94)                 0.825 (0.70-0.90)                   0.044
WET: without extended time.
*
  a correction factor according to the manufacturer specifications was applied in both protocols.



As shown in Table I, the ASSR results, obtained with the                                       approval by the Ethics Committee of the University of Ath-
proposed algorithm, seem to reflect the PTA thresholds in                                      ens, prior to commencing data collection. Participants (or
a more accurate manner, compared to a protocol with no                                         legal guardians) were asked to sign a consent form before
time-extension beyond the 6 minutes. Indeed, the correla-                                      being enrolled in the study.
tion reliability in the proposed protocol was excellent in
all frequencies of both ears, except 4000 Hz in the left ear
                                                                                               References
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