Contralateral suppression of otoacoustic emissions in pre-school children

W Wiktor Jedrzejczak; Edyta Pilka; Piotr Henryk Skarzynski; Henryk Skarzynski

doi:10.1016/j.ijporl.2020.109915

Contralateral suppression of otoacoustic emissions in pre-school children

Int J Pediatr Otorhinolaryngol. 2020 May:132:109915. doi: 10.1016/j.ijporl.2020.109915. Epub 2020 Jan 30.

Authors

W Wiktor Jedrzejczak¹, Edyta Pilka², Piotr Henryk Skarzynski³, Henryk Skarzynski²

Affiliations

¹ Institute of Physiology and Pathology of Hearing, Warsaw, Poland; World Hearing Center, Kajetany, Poland. Electronic address: w.jedrzejczak@ifps.org.pl.
² Institute of Physiology and Pathology of Hearing, Warsaw, Poland; World Hearing Center, Kajetany, Poland.
³ Institute of Physiology and Pathology of Hearing, Warsaw, Poland; World Hearing Center, Kajetany, Poland; Heart Failure and Cardiac Rehabilitation Department, Medical University of Warsaw, Warsaw, Poland; Institute of Sensory Organs, Warsaw, Kajetany, Poland.

PMID: 32028191
DOI: 10.1016/j.ijporl.2020.109915

Abstract

Background: Contralateral suppression of otoacoustic emissions (OAEs) may serve as an index of the medial olivocochlear (MOC) reflex. To date, this index has been studied in various populations but never in pre-school children. The purpose of this study was to fill this gap and describe how the MOC reflex affects the properties of transiently evoked OAEs (TEOAEs) in this age group. In addition, the influence of the presence of spontaneous OAEs (SOAEs) in the studied ear on the suppression of TEOAEs was also investigated.

Methods: TEOAEs with and without contralateral acoustic stimulation (CAS) by white noise were measured in 126 normally hearing pre-school children aged 3-6 years. The values of response levels, suppression by CAS, and signal-to-noise ratios (SNRs) of TEOAEs were investigated for the whole signal (global) and for half-octave frequency bands from 1 to 4 kHz. Only ears with SNR >6 dB were used in the analyses. SOAEs were acquired using the so-called synchronized SOAEs (SSOAEs) technique.

Results: Ears with SSOAEs had higher response levels and SNRs than ears without SSOAEs, and suppression was lower (0.58 dB compared to 0.85 dB). Only 22% of all studied ears had an SNR >20 dB, a level recommended in some studies for measuring suppression. There were no significant effects of age or gender on TEOAE suppression.

Conclusions: Suppression levels for pre-school children did not differ appreciably from those of adults measured under similar conditions in other studies. Taken together with no effect of age in the data studied here, it seems that there is no effect of age on TEOAE suppression. However, we did find that the presence of SSOAEs had an effect on TEOAE suppression, a finding which has not been reported in earlier studies on different populations. We suggest that the presence of SSOAEs might be a crucial factor related to MOC function.

Keywords: Contralateral suppression; Medial olivocochlear system; Spontaneous otoacoustic emission; Transiently evoked otoacoustic emission.

MeSH terms

Acoustic Stimulation / methods
Child
Child, Preschool
Cochlea / physiology
Cochlear Nerve / physiology*
Female
Hearing / physiology
Humans
Male
Neurons, Efferent / physiology
Olivary Nucleus / physiology*
Otoacoustic Emissions, Spontaneous / physiology*
Reflex / physiology
Signal-To-Noise Ratio