Efferent neural control of cochlear mechanics? Olivocochlear bundle stimulation affects cochlear biomechanical nonlinearity

Siegel, Jonathan H.; Kim, Duck O.

doi:10.1016/0378-5955(82)90052-1

Cited by 405 publications

(136 citation statements)

References 30 publications

Supporting

Mentioning

117

Contrasting

Unclassified

Order By: Relevance

“…MOC influence on cochlear mechanics may be noninvasively, though indirectly, explored via measurement of otoacoustic emissions (OAEs) (Mountain 1980;Siegel and Kim 1982). OAEs are sounds recorded in the ear canal (Kemp 1978) that originate as a by-product of cochlear amplification and are sensitive indicators of OHC function.…”

Section: Introductionmentioning

confidence: 99%

“…Conversely, such shifts could contribute significant variability in psychoacoustic measures of MOC effects either across frequency or across individuals. Just as MOC effects on OAEs are known to fluctuate with frequency (e.g., Siegel and Kim 1982;Guinan 1986;Sun 2008;Abdala et al 2009), the effects of CAS on behavioral thresholds may also exhibit fine structure. Understanding such complexities may aid in refining attempts to relate MOCmediated changes in OAEs with performance on psychoacoustic tasks (e.g., Micheyl et al 1995a, b;Garinis et al 2011).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of Contralateral Acoustic Stimulation on Spontaneous Otoacoustic Emissions and Hearing Threshold Fine Structure

Dewey

Lee

Dhar

2014

JARO

View full text Add to dashboard Cite

Medial olivocochlear (MOC) influence on cochlear mechanics can be noninvasively, albeit indirectly, explored via the effects of contralateral acoustic stimulation (CAS) on otoacoustic emissions. CASmediated effects are particularly pronounced for spontaneous otoacoustic emissions (SOAEs), which are typically reduced in amplitude and shifted upward in frequency by CAS. We investigated whether similar frequency shifts and magnitude reductions were observed behaviorally in the fine structure of puretone hearing thresholds, a phenomenon thought to share a common underlying mechanism with SOAEs. In normal-hearing listeners, fine-resolution thresholds were obtained over a narrow frequency range centered on the frequency of an SOAE, both in the absence and presence of 60-dB SPL broadband CAS. While CAS shifted threshold fine structure patterns and SOAEs upward in frequency by a comparable amount, little reduction in the presence or depth of fine structure was observed at frequencies near those of SOAEs. In fact, CAS typically improved thresholds, particularly at threshold minima, and increased fine structure depth when reductions in the amplitude of the associated SOAE were less than 10 dB. Additional measurements made at frequencies distant from SOAEs, or near SOAEs that were more dramatically reduced in amplitude by the CAS, revealed that CAS tended to elevate thresholds and reduce threshold fine structure depth. The results suggest that threshold fine structure is sensitive to MOC-mediated changes in cochlear gain, but that SOAEs complicate the interpretation of threshold measurements at nearby frequencies, perhaps due to masking or other interference effects. Both threshold fine structure and SOAEs may be significant sources of intersubject and intrasubject variability in psychoacoustic investigations of MOC function.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of Contralateral Acoustic Stimulation on Spontaneous Otoacoustic Emissions and Hearing Threshold Fine Structure

Dewey

Lee

Dhar

2014

JARO

View full text Add to dashboard Cite

show abstract

“…As MOC fibers directly innervate OHCs, their activity modifies the input impedance and membrane potential of OHCs (Housley and Ashmore 1991), affecting the mechanical feedback that they provide to basilar membrane motion (Mountain 1980;Siegel and Kim 1982;Murugasu and Russell 1996;Cooper and Guinan 2003). These changes reduce the cochlear-amplifier gain, producing a decrease in auditory-nerve compound action potentials (CAP) and an increase in cochlear microphonics (CM) amplitudes that reflects a higher voltage drop caused by the increase of current flow through OHCs and the cochlear circuit .…”

Section: Introductionmentioning

confidence: 99%

Effects of Electrical Stimulation of Olivocochlear Fibers in Cochlear Potentials in the Chinchilla

Elgueda

Délano

Robles

2011

JARO

View full text Add to dashboard Cite

The mammalian cochlea has two types of sensory cells; inner hair cells, which receive auditory-nerve afferent innervation, and outer hair cells, innervated by efferent axons of the medial olivocochlear (MOC) system. The role of the MOC system in hearing is still controversial. Recently, by recording cochlear potentials in behaving chinchillas, we suggested that one of the possible functions of the efferent system is to reduce cochlear sensitivity during attention to other sensory modalities (Delano et al. in J Neurosci 27:4146-4153, 2007). However, in spite of these compelling results, the physiological effects of electrical MOC activation on cochlear potentials have not been described in detail in chinchillas. The main objective of the present work was to describe these efferent effects in the chinchilla, comparing them with those in other species and in behavioral experiments. We activated the MOC efferent axons in chinchillas with sectioned middle-ear muscles by applying current pulses at the fourth-ventricle floor. Auditory-nerve compound action potentials (CAP) and cochlear microphonics (CM) were acquired in response to clicks and tones of several frequencies, using a round-window electrode. Electrical efferent stimulation produced CAP amplitude suppressions reaching up to 11 dB. They were higher for low to moderate sound levels. Additionally, CM amplitude increments were found, the largest (≤ 2.5 dB) for low intensity tones. CAP suppression was present at all stimulus frequencies, but was greatest for 2 kHz. CM increments were highest for low-frequency tones, and almost absent at high frequencies. We conclude that the effect obtained in chinchilla is similar to but smaller than that observed in cats, and that the effects seen in awake chinchillas, albeit different in magnitude, are consistent with the activation of efferent fibers.

show abstract

“…Current methods that evaluate the efferent modulation of the cochlea often lead to great variability in the direction and magnitude of the response (Siegel and Kim 1982;Moulin et al 1993b;Williams and Brown 1997;Sun 2008b), or are contaminated by other reflexes such as the middle-ear muscle (MEM) reflex (Whitehead et al 1991;Burns et al 1993). Hence, a complete understanding of the efferent modulation of human cochlear functions not only helps elucidate the physiological basis of this phenomenon but also enables potential development of clinical tools for the assessment of the efferent pathway and its role in various pathologies.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Contralateral Acoustic Stimulation on Spontaneous Otoacoustic Emissions

Zhao

Dhar

2009

JARO

View full text Add to dashboard Cite

Evoked otoacoustic emissions are often used to study the medial olivocochlear (MOC) efferents in humans. There has been concern that the emission-evoking stimulus may itself elicit efferent activity and alter the evoked otoacoustic emission. Spontaneous otoacoustic emissions (SOAEs) are hence advantageous as no external stimulation is necessary to record the response in the test ear. Contralateral acoustic stimulation (CAS) has been shown to suppress SOAE level and elevate SOAE frequency, but the time course of these effects is largely unknown. By utilizing the Choi-Williams distribution, here we report a gradual adaptation during the presence of CAS and an overshoot following CAS offset in both SOAE magnitude and frequency from six normal-hearing female human subjects. Furthermore, we have quantified the time constants of both magnitude and frequency shifts at the onset, presence, and offset of four levels of CAS. Most studies using contralateral elicitors do not stringently control the middle-ear muscle (MEM) reflex, leaving the results difficult to interpret. In addition to clinically available measures of the MEM reflex, we have incorporated a sensitive laboratory technique to monitor the MEM reflex in our subjects, allowing us to interpret the results with greater confidence.

show abstract

Efferent neural control of cochlear mechanics? Olivocochlear bundle stimulation affects cochlear biomechanical nonlinearity

Cited by 405 publications

References 30 publications

Effects of Contralateral Acoustic Stimulation on Spontaneous Otoacoustic Emissions and Hearing Threshold Fine Structure

Effects of Contralateral Acoustic Stimulation on Spontaneous Otoacoustic Emissions and Hearing Threshold Fine Structure

Effects of Electrical Stimulation of Olivocochlear Fibers in Cochlear Potentials in the Chinchilla

The Effect of Contralateral Acoustic Stimulation on Spontaneous Otoacoustic Emissions

Contact Info

Product

Resources

About