Evidence for a Cortically Mediated Release from Inhibition in the Human Cochlea

Purpose: To determine cortical influence on the efferent medial olivocochlear bundle system. Research Design: The effects of attention on contralateral suppression (CS) of click-evoked otoacoustic emissions were measured. Study Sample: Fifteen normal-hearing listeners. Results: CS was greatest in the nonattending condition and decreased significantly when attending to the click or broadband noise suppressor. The effects of attention on CS were not frequency dependent or due to changes in recording noise measures. Conclusions: Attention to either the ipsilateral, evoking stimulus or the contralateral suppressor causes a top-down, cortically mediated release from inhibition at the level of the cochlea that is measurable with common audiologic protocols and instrumentation. Future studies assessing the effects of attention on CS of click-evoked otoacoustic emissions in normal controls and individuals with various auditory or attentional deficits may provide valuable information about the capabilities of the cortex to affect peripheral processing in a normal and/or pathological system.

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Neurotoxicity of BFM-95 on the Medial Olivocochlear Bundle Assessed by Means of Contralateral Suppression of 2f1-f2 Distortion Product Otoacoustic Emissions

Otology & Neurotology ◽

10.1097/mao.0b013e31802ce486 ◽

2007 ◽

Vol 28 (2) ◽

pp. 208-212 ◽

Cited By ~ 3

Author(s):

Maria Riga ◽

Stavros Korres ◽

Ioannis Psarommatis ◽

Maria Varvutsi ◽

Ioannis Giotakis ◽

...

Keyword(s):

Otoacoustic Emissions ◽

Distortion Product Otoacoustic Emissions ◽

Olivocochlear Bundle ◽

Distortion Product ◽

Contralateral Suppression ◽

Medial Olivocochlear ◽

Medial Olivocochlear Bundle

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The Influence of Efferent Inhibition on Speech Perception in Noise: A Revisit Through Its Level-Dependent Function

American Journal of Audiology ◽

10.1044/2019_aja-ind50-18-0098 ◽

2019 ◽

Vol 28 (2S) ◽

pp. 508-515

Author(s):

L. Yashaswini ◽

Sandeep Maruthy

Keyword(s):

Speech Perception ◽

Broadband Noise ◽

Speech Perception In Noise ◽

Contralateral Noise ◽

Olivocochlear Bundle ◽

Efferent Inhibition ◽

Dependent Function ◽

Contralateral Suppression ◽

Medial Olivocochlear ◽

Medial Olivocochlear Bundle

Purpose The study aimed to assess the relationship between the level-dependent function of efferent inhibition and speech perception in noise across different intensities of suppressor and across different signal-to-noise ratios (SNRs) of speech. Method Twenty-six young normal-hearing adults participated in the study. Contralateral suppression of transient evoked otoacoustic emissions (TEOAEs) was measured for 3 levels of suppressor (40, 50, and 60 dB SPL). Speech identification score (SIS) was measured at 5 ipsilateral SNR conditions (quiet, 0, −5, −10, and −15 dB), with and without contralateral broadband noise at 3 levels (40, 50, and 60 dB SPL). Furthermore, SNR-50 was measured with and without the same 3 levels of contralateral broadband noise. Results The results showed that the suppression magnitude of TEOAE increased with an increase in suppressor level. However, neither SIS nor SNR-50 was influenced by the contralateral noise. In addition, SIS and SNR-50 did not show significant correlation with contralateral suppression of TEOAEs. This was true at all the SNRs and contralateral noise levels used in the study. Conclusions The findings suggest that the intensity of noise directly influences medial olivocochlear bundle–mediated efferent inhibition. However, the role of the medial olivocochlear bundle in regulating speech perception in noise needs to be revisited. Supplemental Material https://doi.org/10.23641/asha.9336353

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Increased contralateral suppression of otoacoustic emissions indicates a hyperresponsive medial olivocochlear system in humans with tinnitus and hyperacusis

Journal of Neurophysiology ◽

10.1152/jn.00576.2014 ◽

2014 ◽

Vol 112 (12) ◽

pp. 3197-3208 ◽

Cited By ~ 39

Author(s):

Inge M. Knudson ◽

Christopher A. Shera ◽

Jennifer R. Melcher

Keyword(s):

Brain Stem ◽

Cochlear Nucleus ◽

Otoacoustic Emissions ◽

Sound Level ◽

Broadband Noise ◽

Neural Pathways ◽

Distortion Product ◽

Olivocochlear System ◽

Contralateral Suppression ◽

Medial Olivocochlear

Atypical medial olivocochlear (MOC) feedback from brain stem to cochlea has been proposed to play a role in tinnitus, but even well-constructed tests of this idea have yielded inconsistent results. In the present study, it was hypothesized that low sound tolerance (mild to moderate hyperacusis), which can accompany tinnitus or occur on its own, might contribute to the inconsistency. Sound-level tolerance (SLT) was assessed in subjects (all men) with clinically normal or near-normal thresholds to form threshold-, age-, and sex-matched groups: 1) no tinnitus/high SLT, 2) no tinnitus/low SLT, 3) tinnitus/high SLT, and 4) tinnitus/low SLT. MOC function was measured from the ear canal as the change in magnitude of distortion-product otoacoustic emissions (DPOAE) elicited by broadband noise presented to the contralateral ear. The noise reduced DPOAE magnitude in all groups (“contralateral suppression”), but significantly more reduction occurred in groups with tinnitus and/or low SLT, indicating hyperresponsiveness of the MOC system compared with the group with no tinnitus/high SLT. The results suggest hyperresponsiveness of the interneurons of the MOC system residing in the cochlear nucleus and/or MOC neurons themselves. The present data, combined with previous human and animal data, indicate that neural pathways involving every major division of the cochlear nucleus manifest hyperactivity and/or hyperresponsiveness in tinnitus and/or low SLT. The overactivation may develop in each pathway separately. However, a more parsimonious hypothesis is that top-down neuromodulation is the driving force behind ubiquitous overactivation of the auditory brain stem and may correspond to attentional spotlighting on the auditory domain in tinnitus and hyperacusis.

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

Frontiers in Neuroscience ◽

10.3389/fnins.2021.746821 ◽

2021 ◽

Vol 15 ◽

Author(s):

Sriram Boothalingam ◽

Shawn S. Goodman ◽

Hilary MacCrae ◽

Sumitrajit Dhar

Keyword(s):

Auditory Processing ◽

Otoacoustic Emissions ◽

Time Course ◽

Broadband Noise ◽

Activity Data ◽

Medial Olivocochlear Reflex ◽

Clinical Method ◽

Click Train ◽

Auditory Efferent System ◽

Medial Olivocochlear

The auditory efferent system, especially the medial olivocochlear reflex (MOCR), is implicated in both typical auditory processing and in auditory disorders in animal models. Despite the significant strides in both basic and translational research on the MOCR, its clinical applicability remains under-utilized in humans due to the lack of a recommended clinical method. Conventional tests employ broadband noise in one ear while monitoring change in otoacoustic emissions (OAEs) in the other ear to index efferent activity. These methods, (1) can only assay the contralateral MOCR pathway and (2) are unable to extract the kinetics of the reflexes. We have developed a method that re-purposes the same OAE-evoking click-train to also concurrently elicit bilateral MOCR activity. Data from click-train presentations at 80 dB peSPL at 62.5 Hz in 13 young normal-hearing adults demonstrate the feasibility of our method. Mean MOCR magnitude (1.7 dB) and activation time-constant (0.2 s) are consistent with prior MOCR reports. The data also suggest several advantages of this method including, (1) the ability to monitor MEMR, (2) obtain both magnitude and kinetics (time constants) of the MOCR, (3) visual and statistical confirmation of MOCR activation.

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Contralateral Suppression of Transient Otoacoustic Emissions and Sentence Recognition in Noise in Young Adults

Journal of the American Academy of Audiology ◽

10.3766/jaaa.23.9.3 ◽

2012 ◽

Vol 23 (09) ◽

pp. 686-696 ◽

Cited By ~ 17

Author(s):

Andrew Stuart ◽

Alyson K. Butler

Keyword(s):

Young Adults ◽

Otoacoustic Emissions ◽

Normal Hearing ◽

Signal To Noise ◽

Sentence Recognition ◽

Contralateral Suppression ◽

Significant Difference ◽

Continuous Noise ◽

Medial Olivocochlear ◽

Release From Masking

Background: One purported role of the medial olivocochlear (MOC) efferent system is to reduce the effects of masking noise. MOC system functioning can be evaluated noninvasively in humans through contralateral suppression of otoacoustic emissions. It has been suggested that the strength of the MOC efferent activity should be positively associated with listening performance in noise. Purpose: The objective of the study was to further explore this notion by examining contralateral suppression of transient evoked otoacoustic emissions (TEOAEs) and sentence recognition in two noises with normal hearing young adults. Research Design: A repeated measures multivariate quasi-experimental design was employed. Study Sample: Thirty-two normal hearing young adult females participated. Data Collection and Analysis: Reception thresholds for sentences (RTSs) were determined monaurally and binaurally in quiet and in competing continuous and interrupted noises. Both noises had an identical power spectrum and differed only in their temporal continuity. “Release from masking” was computed by subtracting RTS signal-to-noise ratios in interrupted from continuous noise. TEOAEs were evoked with 80 dB peSPL click stimuli. To examine contralateral suppression, TEOAEs were evaluated with 60 dB peSPL click stimuli with and without a contralateral 65 dB SPL white noise suppressor. Results: A binaural advantage was observed for RTSs in quiet and noise (p < .0001) while there was no difference between ears (p >.05). In noise, performance was superior in the interrupted noise (i.e., RTSs were lower vs. continuous noise; p < .0001). There were no statistically significant differences in TEOAE levels between ears (p >.05). There was also no significant difference in the amount of suppression between ears (p = .41). There were no significant correlations or predictive linear relations between the amount of TEOAE suppression and any indices of sentence recognition in noise (i.e., RTS signal-to-noise ratios and release from masking; p > .05). Conclusions: The findings are not consistent with the notion that increased medial olivocochlear efferent feedback, as assessed via contralateral suppression of TEOAEs, is associated with improved speech perception in continuous and interrupted noise.

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What is the role of the medial olivocochlear system in speech-in-noise processing?

Journal of Neurophysiology ◽

10.1152/jn.00222.2011 ◽

2012 ◽

Vol 107 (5) ◽

pp. 1301-1312 ◽

Cited By ~ 41

Author(s):

Jessica de Boer ◽

A. Roger D. Thornton ◽

Katrin Krumbholz

Keyword(s):

Otoacoustic Emissions ◽

Noise Masking ◽

Speech In Noise ◽

Olivocochlear System ◽

Contralateral Suppression ◽

Auditory Brain Stem ◽

Medial Olivocochlear System ◽

Masking Noise ◽

Cochlear Gain ◽

Medial Olivocochlear

The medial olivocochlear (MOC) bundle reduces the gain of the cochlear amplifier through reflexive activation by sound. Physiological results indicate that MOC-induced reduction in cochlear gain can enhance the response to signals when presented in masking noise. Some previous studies suggest that this “antimasking” effect of the MOC system plays a role in speech-in-noise perception. The present study set out to reinvestigate this hypothesis by correlating measures of MOC activity and speech-in-noise processing across a group of normal-hearing participants. MOC activity was measured using contralateral suppression of otoacoustic emissions (OAEs), and speech-in-noise processing was measured by measuring the effect of noise masking on performance in a consonant-vowel (CV) discrimination task and on auditory brain stem responses evoked by a CV syllable. Whereas there was a significant correlation between OAE suppression and both measures of speech-in-noise processing, the direction of this correlation was opposite to that predicted by the antimasking hypothesis, in that individuals with stronger OAE suppression tended to show greater noise-masking effects on CV processing. The current results indicate that reflexive MOC activation is not always beneficial to speech-in-noise processing. We propose an alternative to the antimasking hypothesis, whereby the MOC system benefits speech-in-noise processing through dynamic (e.g., attention- and experience-dependent), rather than reflexive, control of cochlear gain.

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Heightened visual attention does not affect inner ear function as measured by otoacoustic emissions

PeerJ ◽

10.7717/peerj.4199 ◽

2017 ◽

Vol 5 ◽

pp. e4199 ◽

Cited By ~ 5

Author(s):

W. Wiktor Jedrzejczak ◽

Rafal Milner ◽

Lukasz Olszewski ◽

Henryk Skarzynski

Keyword(s):

Visual Attention ◽

Inner Ear ◽

Otoacoustic Emissions ◽

Visual Stimuli ◽

Acoustic Stimulation ◽

Broadband Noise ◽

Contralateral Acoustic Stimulation ◽

Active Condition ◽

Medial Olivocochlear ◽

Stimulation Of

Previous research has indicated that inner ear function might be modulated by visual attention, although the results have not been totally conclusive. Conceivably, modulation of hearing might occur due to stimulation of the cochlea via descending medial olivocochlear (MOC) neurons. The aim of the present study was to test whether increased visual attention caused corresponding changes in inner ear function, which was measured by the strength of otoacoustic emissions (OAEs) recorded from the ear canal in response to a steady train of clicks. To manipulate attention, we asked subjects to attend to, or ignore, visual stimuli delivered according to an odd-ball paradigm. The subjects were presented with two types of visual stimuli: standard and deviant (20% of all stimuli, randomly presented). During a passive part of the experiment, subjects had to just observe a pattern of squares on a computer screen. In an active condition, the subject’s task was to silently count the occasional inverted (deviant) pattern on the screen. At all times, visual evoked potentials (VEPs) were used to objectively gauge the subject’s state of attention, and OAEs in response to clicks (transiently evoked OAEs, TEOAEs) were used to gauge inner ear function. As a test of descending neural activity, TEOAE levels were evaluated with and without contralateral acoustic stimulation (CAS) by broadband noise, a paradigm known to activate the MOC pathway. Our results showed that the recorded VEPs were, as expected, a good measure of visual attention, but even when attention levels changed there was no corresponding change in TEOAE levels. We conclude that visual attention does not significantly affect inner ear function.

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