Efferent‐mediated control of basilar membrane motion

Cooper, Nigel P.; Guinan, John J.

doi:10.1113/jphysiol.2006.114991

Cited by 156 publications

(161 citation statements)

References 44 publications

Supporting

Mentioning

144

Contrasting

Unclassified

Order By: Relevance

“…It is possible, however, that these two mouse strains exhibit different MEM and MOC strengths, which has yet to be fully examined. Discrepancies between the results reported here for TEOAEs and those by Chambers and colleagues for DPOAEs may also relate to the different emissions being monitored [1,2]. Variability in the status of anesthesia during the recovery period might also explain the lower incidence of delayed MOCrelated changes in the TEOAEs reported here.…”

Section: Discussioncontrasting

confidence: 55%

Separating medial olivocochlear from acoustic reflex effects on transient evoked otoacoustic emissions in unanesthetized mice

Xu¹,

Cheatham²,

Siegel³

2015

AIP Conference Proceedings

View full text Add to dashboard Cite

Abstract. Descending neural pathways in the mammalian auditory system are believed to modulate the function of the peripheral auditory system [3,8,10]. These pathways include the medial olivocochlear (MOC) efferent innervation to the cochlear outer hair cells (OHCs) and the acoustic reflex pathways mediating middle ear muscle (MEM) contractions. The MOC effects can be monitored noninvasively using otoacoustic emissions (OAEs) [5,6], which are acoustic byproducts of cochlear function [7]. In this study, we applied a sensitive method to determine when and to what degree contralateral MEM suppression contaminated MOC efferent effects on TEOAEs in unanesthetized mice. The lowest contralateral broadband noise evoking MEM contractions varied across animals. Examples of potential MOC-mediated TEOAE suppression with contralateral noise below MEM contraction thresholds were seen, but this behavior did not occur in the majority of cases.

show abstract

Section: Discussioncontrasting

confidence: 55%

Separating medial olivocochlear from acoustic reflex effects on transient evoked otoacoustic emissions in unanesthetized mice

Xu¹,

Cheatham²,

Siegel³

2015

AIP Conference Proceedings

View full text Add to dashboard Cite

show abstract

“…MOC efferents act upon outer hair cells, inhibiting the mechanical gain in the cochlea for low-and moderate-intensity sounds (Cooper and Guinan 2006) and may be activated involuntarily (i.e., in a reflexive manner) by ipsilateral and/or contralateral sounds (Guinan 2006). This suggests that auditory sensitivity and dynamic range could be dynamically and adaptively varying during natural, binaural listening depending on the state of activation of MOC efferents.…”

Section: Introductionmentioning

confidence: 99%

Roles of the Contralateral Efferent Reflex in Hearing Demonstrated with Cochlear Implants

Lopez‐Poveda

Eustaquio-Martín

Stohl³

et al. 2016

Advances in Experimental Medicine and Biology

View full text Add to dashboard Cite

Our two ears do not function as fixed and independent sound receptors; their functioning is coupled and dynamically adjusted via the contralateral medial olivocochlear efferent reflex (MOCR). The MOCR possibly facilitates speech recognition in noisy environments. Such a role, however, is yet to be demonstrated because selective deactivation of the reflex during natural acoustic listening has not been possible for human subjects up until now. Here, we propose that this and other roles of the MOCR may be elucidated using the unique stimulus controls provided by cochlear implants (CIs). Pairs of sound processors were constructed to mimic or not mimic the effects of the contralateral MOCR with CIs. For the non-mimicking condition (STD strategy), the two processors in a pair functioned independently of each other. When configured to mimic the effects of the MOCR (MOC strategy), however, the two processors communicated with each other and the amount of compression in a given frequency channel of each processor in the pair decreased 106 E. A. Lopez-Poveda et al. with increases in the output energy from the contralateral processor. The analysis of output signals from the STD and MOC strategies suggests that in natural binaural listening, the MOCR possibly causes a small reduction of audibility but enhances frequency-specific inter-aural level differences and the segregation of spatially nonoverlapping sound sources. The proposed MOC strategy could improve the performance of CI and hearing-aid users.

show abstract

“…1). At the signal frequency place, the BM response to the 1.2-kHz masker should be approximately linear, even with MOCR stimulation (Cooper and Guinan 2006). The 2.4-kHz masker frequency was chosen because it has produced substantial suppression of a 2-kHz masker in previous studies with young adults (Shannon 1976;Sommers and Gehr 2010).…”

Section: Stimulimentioning

confidence: 99%

“…The MOCR is a sound-elicited efferent feedback loop that reduces OHC amplification or gain (Cooper and Guinan 2006). Gain starts to be affected approximately 25 ms after elicitor onset.…”

Section: Introductionmentioning

confidence: 99%

Aging Effects on Behavioural Estimates of Suppression with Short Suppressors

Hegland

Strickland

2016

Advances in Experimental Medicine and Biology

View full text Add to dashboard Cite

Auditory two-tone suppression is a nearly instantaneous reduction in the response of the basilar membrane to a tone or noise when a second tone or noise is presented simultaneously. Previous behavioural studies provide conflicting evidence on whether suppression changes with increasing age, and aging effects may depend on whether a suppressor above (high-side) or below (low-side) the signal frequency is used. Most previous studies have measured suppression using stimuli long enough to elicit the medial olivocochlear reflex (MOCR), a soundelicited reflex that reduces cochlear amplification or gain. It has a "sluggish" onset of approximately 25 ms. There is physiological evidence that suppression may be reduced or altered by elicitation of the MOCR. In the present study, suppression was measured behaviourally in younger adults and older adults using a forward-masking paradigm with 20-ms and 70-ms maskers and suppressors. In experiment 1, gain was estimated by comparing on-frequency (2 kHz) and off-frequency (1.2 kHz) masker thresholds for a short, fixed-level 2-kHz signal. In experiment 2, the fixedlevel signal was preceded by an off-frequency suppressor (1.2 or 2.4 kHz) presented simultaneously with the on-frequency masker. A suppressor level was chosen that did not produce any forward masking of the signal. Suppression was measured as the difference in on-frequency masker threshold with and without the suppressor present. The effects of age on gain and suppression estimates will be discussed.

show abstract

Efferent‐mediated control of basilar membrane motion

Cited by 156 publications

References 44 publications

Separating medial olivocochlear from acoustic reflex effects on transient evoked otoacoustic emissions in unanesthetized mice

Separating medial olivocochlear from acoustic reflex effects on transient evoked otoacoustic emissions in unanesthetized mice

Roles of the Contralateral Efferent Reflex in Hearing Demonstrated with Cochlear Implants

Aging Effects on Behavioural Estimates of Suppression with Short Suppressors

Contact Info

Product

Resources

About