Evidence of inner ear contribution in bone conduction in chinchilla

Chhan, David; Röösli, Christof; McKinnon, Melissa L.; Rosowski, John J.

doi:10.1016/j.heares.2012.11.014

Cited by 30 publications

(24 citation statements)

References 12 publications

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“…This result is consistent with the hypothesis that the cochlear acoustic and mechanical events that lead to stimulation of the sensory cells within the hearing organ are common to both AC and BC stimulation, regardless of the signal conduction pathway (e.g. Stenfelt et al 2003; Chhan et al 2013). Demonstrations of the similarity of BC induced cochlear sound pressures and cochlear potential are consistent with this hypothesis (Chhan 2013).…”

Section: Introductionsupporting

confidence: 91%

“…Previous work in our laboratory (Songer et al 2008; Chhan et al 2013) suggests inner ear mechanisms contribute significantly to bone conduction in chinchillas. We also observed an imbalance in the effect of ossicular interruption on the sound pressures produced in scala vestibuli P SV and tympani P ST by vibration of the skull, which we hypothesized was due to the interruption-induced decrease in load impedance on the oval window that would impede the sound produced by inner-ear sources of BC stimulation (Chhan et al 2013).…”

Section: Introductionmentioning

confidence: 73%

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Middle-ear and inner-ear contribution to bone conduction in chinchilla: The development of Carhart's notch

et al. 2016

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While the cochlea is considered the primary site of the auditory response to bone conduction (BC) stimulation, the paths by which vibratory energy applied to the skull (or other structures) reaches the inner ear are a matter of continued investigation. We present acoustical measurements of sound in the inner ear that separate out the components of BC stimulation that stimulate the inner ear via ossicular motion (compression of the walls of the ear canal or ossicular inertia) from the components that act directly on the cochlea (cochlear compression or inertia, and extra-cochlear ‘third-window’ pathways). The results are consistent with our earlier suggestion that the inner-ear mechanisms play a large role in bone-conduction stimulation in the chinchilla at all frequencies. However, the data also suggest the pathways that conduct vibration to the inner ear via ossicular-motion make a significant contribution to the response to BC stimulation in the 1 to 3 kHz range, such that interruption of these path leads to a 5 dB reduction in total stimulation in that frequency range. The mid-frequency reduction produced by ossicular manipulations is similar to the ‘Carhart's notch’ phenomenon observed in otology and audiology clinics in cases of human ossicular disorders. We also present data consistent with much of the ossicular-conducted sound in chinchilla depending on occlusion of the ear canal.

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Section: Introductionsupporting

confidence: 91%

Section: Introductionmentioning

confidence: 73%

Middle-ear and inner-ear contribution to bone conduction in chinchilla: The development of Carhart's notch

et al. 2016

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“…P ST might also be affected by sound pressure outside the RW (Peake et al, 1992) but our measurements of ME sound pressure outside the OW [Fig. 2(B)] and RW are at least 40 dB lower than P V , and measurements of ME sound pressure with an intact or open ME (personal communication from D. C. Chhan, 2012) demonstrate that the effects of ME sound pressures outside the OW and RW are negligible.…”

Section: Estimated Effect Of Opening the Mementioning

confidence: 63%

“…Mathematical techniques may provide a description of the effects of the cochlear holes sufficient for a correction (Ravicz and Rosowski, 2012a), or different approaches to the cochlear vestibule (for example, through a posterior cranial fossa; Chhan et al, 2012) may overcome this problem.…”

Section: Possible Evidence Of Traveling-wave Effectsmentioning

confidence: 99%

Inner-ear sound pressures near the base of the cochlea in chinchilla: Further investigation

Ravicz

Rosowski

2013

The Journal of the Acoustical Society of America

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The middle-ear pressure gain GMEP, the ratio of sound pressure in the cochlear vestibule PV to sound pressure at the tympanic membrane PTM, is a descriptor of middle-ear sound transfer and the cochlear input for a given stimulus in the ear canal. GMEP and the cochlear partition differential pressure near the cochlear base ΔPCP, which determines the stimulus for cochlear partition motion and has been linked to hearing ability, were computed from simultaneous measurements of PV, PTM, and the sound pressure in scala tympani near the round window PST in chinchilla. GMEP magnitude was approximately 30 dB between 0.1 and 10 kHz and decreased sharply above 20 kHz, which is not consistent with an ideal transformer or a lossless transmission line. The GMEP phase was consistent with a roughly 50-μs delay between PV and PTM. GMEP was little affected by the inner-ear modifications necessary to measure PST. GMEP is a good predictor of ΔPCP at low and moderate frequencies where PV >> PST but overestimates ΔPCP above a few kilohertz where PV ≈ PST. The ratio of PST to PV provides insight into the distribution of sound pressure within the cochlear scalae.

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“…Velocities were measured with a Polytec CLV-1000 laser-Doppler vibrometer on small glass reflective bead targets on the stapes (V S ), piezo stimulator tip, round window, and petrous bone. Sound pressure in the cochlear vestibule P V was measured with a fiber-optic pressure sensor [2] that fit closely into a small hole in the vestibule via the braincase after removing part of the paraflocculus [11]. (All variables in bold are complex spectra.)…”

Section: Stimuli and Responsesmentioning

confidence: 99%

Middle-ear mechanics in chinchilla when stimulated in reverse: Predictions and measurements

Ravicz¹,

Bowers²,

Rosowski³

2018

AIP Conference Proceedings

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Abstract. The properties of the middle ear (ME) when driven from the cochlea ("in reverse") are important for evaluating otoacoustic emissions (OAEs) and may be quite different from middle-ear function with normal ("forward") sound transmission. In chinchilla, a species commonly used for auditory research (especially for noise hazard and OAE studies), we measured ear-canal and inner-ear sound pressures and stapes velocity while stimulating the middle ear with sound or in reverse with an actuator on the round window. We compute (1) admittances at the border between the middle and inner ear: the cochlear input admittance Y C , the load seen by the ME with normal sound transmission, and the reverse middle-ear input admittance , the load the ME exerts on the cochlea for reverse transmission such as OAEs, and (2) a metric of middle-ear function with reverse stimulation: The reverse ME pressure gain between the cochlear vestibule and the ear canal, for different ear canal conditions. The sensitivity of and to changes in ear canal termination provides insight into the effect of ear-canal conditions on OAEs and flexibility in the middle ear, while a comparison of the admittances provides an estimate of power absorption and reflection at the boundary between the middle and inner ear. Measurements support predictions from a middle-ear two-port transmission-matrix model based on measurements with forward stimulation.

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Evidence of inner ear contribution in bone conduction in chinchilla

Cited by 30 publications

References 12 publications

Middle-ear and inner-ear contribution to bone conduction in chinchilla: The development of Carhart's notch

Middle-ear and inner-ear contribution to bone conduction in chinchilla: The development of Carhart's notch

Inner-ear sound pressures near the base of the cochlea in chinchilla: Further investigation

Middle-ear mechanics in chinchilla when stimulated in reverse: Predictions and measurements

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