The Medial Olivocochlear Reflex Is Unlikely to Play a Role in Listening Difficulties in Children

Abstract

The medial olivocochlear reflex (MOCR) has been implicated in several auditory processes. The putative role of the MOCR in improving speech perception in noise is particularly relevant for children who complain of listening difficulties (LiD). The hypothesis that the MOCR may be impaired in individuals with LiD or auditory processing disorder has led to several investigations but without consensus. In two related studies, we compared the MOCR functioning of children with LiD and typically developing (TD) children in the same age range (7–17 years). In Study 1, we investigated ipsilateral, contralateral, and bilateral MOCR using forward-masked click-evoked otoacoustic emissions (CEOAEs; n = 17 TD, 17 LiD). In Study 2, we employed three OAE types: CEOAEs ( n = 16 TD, 21 LiD), stimulus frequency OAEs ( n = 21 TD, 30 LiD), and distortion product OAEs ( n = 17 TD, 22 LiD) in a contralateral noise paradigm. Results from both studies suggest that the MOCR functioning is not significantly different between the two groups. Some likely reasons for differences in findings among published studies could stem from the lack of strict data quality measures (e.g., high signal-to-noise ratio, control for the middle ear muscle reflex) that were enforced in the present study. The inherent variability of the MOCR, the subpar reliability of current MOCR methods, and the heterogeneity in auditory processing deficits that underlie auditory processing disorder make detecting clinically relevant differences in MOCR function impractical using current methods.

No Change in Medial Olivocochlear Efferent Activity during an Auditory or Visual Task: Dual Evidence from Otoacoustic Emissions and Event-Related Potentials

“…This is in line with some other studies that failed to confirm earlier reported effects on the MOC reflex, for example, there are studies that have failed to show any connection between the MOC reflex and gender or laterality [ 46 ], adaptation to noise and central auditory processing [ 39 , 40 ], auditory processing disorders [ 47 ], tinnitus [ 48 ], or sickle cell disease [ 49 ]. Specifically, it has been suggested that previous work on auditory processing disorders probably did not fulfill appropriate SNR criteria in order to ensure reliability [ 47 ]. Nevertheless, despite the abovementioned findings, we do not completely discard the possibility that there is cooperation between ear and cortex when switching between modalities.…”

A Time-Course-Based Estimation of the Human Medial Olivocochlear Reflex Function Using Clicks

“…(1) As expected based on binaural integration, bilateral stimulation produced larger, more than twice the MOCR inhibition (1.69 ± 1.2 dB; ± 1SD) relative to right (0.61 ± 0.4 dB) and left (0.62 ± 0.4 dB) ear-only stimulation. This is consistent with several prior reports (Berlin et al, 1995;Backus and Guinan, 2007;Lilaonitkul and Guinan, 2009a;Boothalingam et al, 2018Boothalingam et al, , 2019. ( 2) At least for the bilateral stimulation, not all frequencies (Figure 6; Bilateral Panel) appear to be inhibited to the same extent.…”

Efeito inibitório da via eferente auditiva no transtorno de processamento auditivo central

“…Esse dado foi importante, pois revelou que os grupos eram definitivamente diferentes quanto à maneira como o sistema auditivo processa a informação acústica. Na maioria dos estudos consultados, a amostra de crianças típicas é selecionada em função apenas da ausência de queixas de PAC (7,8,10,16,17) , o que poderia levar a viés amostral. A realização da avaliação do PAC em todas as crianças pode ser considerada como um diferencial importante na condução do presente estudo, separando os indivíduos com e sem alteração de forma mais criteriosa.…”