The Experts below are selected from a list of 3948 Experts worldwide ranked by ideXlab platform
Richard L. Goode - One of the best experts on this subject based on the ideXlab platform.
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Basilar Membrane and osseous spiral lamina motion in human cadavers with air and bone conduction stimuli
Hearing Research, 2003Co-Authors: Stefan Stenfelt, Sunil Puria, Naohito Hato, Richard L. GoodeAbstract:Basilar Membrane and osseous spiral lamina motion in human cadavers with air and bone conduction stimuli
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Basilar Membrane and osseous spiral lamina motion in human cadavers with air and bone conduction stimuli
Hearing Research, 2003Co-Authors: Stefan Stenfelt, Sunil Puria, Naohito Hato, Richard L. GoodeAbstract:It is generally accepted that bone conduction (BC) stimuli yield a traveling wave on the Basilar Membrane (BM) and hence stimulate the cochlea by the same mechanisms as normal air conduction (AC). The basis for this is the ability to cancel or mask a BC tone with an AC tone and the ability to generate two tone distortion products with a BC tone and an AC tone. The hypothesis is proposed that BC stimulates the BM not only through the hydrodynamics of the scala vestibuli and scala tympani, but also through osseous spiral lamina (OSL) vibrations. To test this hypothesis the BM and OSL response with AC as well as BC stimulation was measured with a laser Doppler vibrometer. Human temporal bones mounted on a shaker were used to record the velocities of the bone per se, the BM and the OSL. The measurements were then converted to relative BM and OSL velocities. The results from the basal turn of the cochlea show similar behavior with AC and BC stimulation. The motion of the OSL at the edge where it connects to the BM is in phase and is typically 6 dB lower than the BM motion. With BC stimulation, there is less phase accumulation in the OSL after the cochlea is drained; the OSL moves due to inertial forces and resonates at approximately 7 kHz. Inertial vibration of the OSL may partially contribute to the total response of BC sound, especially at the high frequencies, although current models of the cochlea assume a rigid OSL. The measurements reported here can be used to include a flexible OSL in cochlear models.
Stefan Stenfelt - One of the best experts on this subject based on the ideXlab platform.
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Basilar Membrane and osseous spiral lamina motion in human cadavers with air and bone conduction stimuli
Hearing Research, 2003Co-Authors: Stefan Stenfelt, Sunil Puria, Naohito Hato, Richard L. GoodeAbstract:Basilar Membrane and osseous spiral lamina motion in human cadavers with air and bone conduction stimuli
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Basilar Membrane and osseous spiral lamina motion in human cadavers with air and bone conduction stimuli
Hearing Research, 2003Co-Authors: Stefan Stenfelt, Sunil Puria, Naohito Hato, Richard L. GoodeAbstract:It is generally accepted that bone conduction (BC) stimuli yield a traveling wave on the Basilar Membrane (BM) and hence stimulate the cochlea by the same mechanisms as normal air conduction (AC). The basis for this is the ability to cancel or mask a BC tone with an AC tone and the ability to generate two tone distortion products with a BC tone and an AC tone. The hypothesis is proposed that BC stimulates the BM not only through the hydrodynamics of the scala vestibuli and scala tympani, but also through osseous spiral lamina (OSL) vibrations. To test this hypothesis the BM and OSL response with AC as well as BC stimulation was measured with a laser Doppler vibrometer. Human temporal bones mounted on a shaker were used to record the velocities of the bone per se, the BM and the OSL. The measurements were then converted to relative BM and OSL velocities. The results from the basal turn of the cochlea show similar behavior with AC and BC stimulation. The motion of the OSL at the edge where it connects to the BM is in phase and is typically 6 dB lower than the BM motion. With BC stimulation, there is less phase accumulation in the OSL after the cochlea is drained; the OSL moves due to inertial forces and resonates at approximately 7 kHz. Inertial vibration of the OSL may partially contribute to the total response of BC sound, especially at the high frequencies, although current models of the cochlea assume a rigid OSL. The measurements reported here can be used to include a flexible OSL in cochlear models.
Sunil Puria - One of the best experts on this subject based on the ideXlab platform.
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the pectinate zone is stiff and the arcuate zone determines passive Basilar Membrane mechanics in the gerbil
AIP Conference Proceedings, 2018Co-Authors: Hongyi Xia, Charles R Steele, Sunil PuriaAbstract:The gerbil Basilar Membrane (BM) differs from other mammalian BMs in that the lower collagen-fiber layer of the pectinate zone (PZ) forms an arch, the upper fiber layer is flat, and ground substance separates the two layers. The role of this arch has been unknown, but can be elucidated by models. In the standard simple beam model (SBM), the upper and lower collagen-fiber layers of the BM are represented as a single layer in both the PZ and the arcuate zone (AZ). In our new arch-beam model (ABM), the upper fiber layer is flat, the lower layer forms an arch in the PZ, and the two layers combine to form the flat portion of the BM in the AZ. This design is incorporated into a 3D finite-element tapered-box model of the cochlea with viscous fluid. We find in the model that the PZ rotates as a rigid body, so its specific properties have little influence, while the AZ thickness and collagen volume fraction primarily determine passive BM mechanics.The gerbil Basilar Membrane (BM) differs from other mammalian BMs in that the lower collagen-fiber layer of the pectinate zone (PZ) forms an arch, the upper fiber layer is flat, and ground substance separates the two layers. The role of this arch has been unknown, but can be elucidated by models. In the standard simple beam model (SBM), the upper and lower collagen-fiber layers of the BM are represented as a single layer in both the PZ and the arcuate zone (AZ). In our new arch-beam model (ABM), the upper fiber layer is flat, the lower layer forms an arch in the PZ, and the two layers combine to form the flat portion of the BM in the AZ. This design is incorporated into a 3D finite-element tapered-box model of the cochlea with viscous fluid. We find in the model that the PZ rotates as a rigid body, so its specific properties have little influence, while the AZ thickness and collagen volume fraction primarily determine passive BM mechanics.
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unraveling the mystery of hearing in gerbil and other rodents with an arch beam model of the Basilar Membrane
Scientific Reports, 2017Co-Authors: S Kapuria, Charles R Steele, Sunil PuriaAbstract:The mammalian Basilar Membrane (BM) consists of two collagen-fiber layers responsible for the frequency-to-place tonotopic mapping in the cochlea, which together form a flat beam over at least part of the BM width. The mechanics of hearing in rodents such as gerbil pose a challenge to our understanding of the cochlea, however, because for gerbil the two layers separate to form a pronounced arch over the remaining BM width. Moreover, the thickness and total width normally thought to determine the local stiffness, and tonotopic mapping in turn, change little along the cochlear length. A nonlinear analysis of a newly developed model, incorporating flat upper and arched lower fiber layers connected by ground substance, explains the initial plateau and subsequent quadratic increase found in measured stiffness vs. deflection curves under point loading, while for pressure loading the model accurately predicts the tonotopic mapping. The model also has applicability to understanding cochlear development and to interpreting evolutionary changes in mammalian hearing.
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Basilar Membrane and osseous spiral lamina motion in human cadavers with air and bone conduction stimuli
Hearing Research, 2003Co-Authors: Stefan Stenfelt, Sunil Puria, Naohito Hato, Richard L. GoodeAbstract:Basilar Membrane and osseous spiral lamina motion in human cadavers with air and bone conduction stimuli
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Basilar Membrane and osseous spiral lamina motion in human cadavers with air and bone conduction stimuli
Hearing Research, 2003Co-Authors: Stefan Stenfelt, Sunil Puria, Naohito Hato, Richard L. GoodeAbstract:It is generally accepted that bone conduction (BC) stimuli yield a traveling wave on the Basilar Membrane (BM) and hence stimulate the cochlea by the same mechanisms as normal air conduction (AC). The basis for this is the ability to cancel or mask a BC tone with an AC tone and the ability to generate two tone distortion products with a BC tone and an AC tone. The hypothesis is proposed that BC stimulates the BM not only through the hydrodynamics of the scala vestibuli and scala tympani, but also through osseous spiral lamina (OSL) vibrations. To test this hypothesis the BM and OSL response with AC as well as BC stimulation was measured with a laser Doppler vibrometer. Human temporal bones mounted on a shaker were used to record the velocities of the bone per se, the BM and the OSL. The measurements were then converted to relative BM and OSL velocities. The results from the basal turn of the cochlea show similar behavior with AC and BC stimulation. The motion of the OSL at the edge where it connects to the BM is in phase and is typically 6 dB lower than the BM motion. With BC stimulation, there is less phase accumulation in the OSL after the cochlea is drained; the OSL moves due to inertial forces and resonates at approximately 7 kHz. Inertial vibration of the OSL may partially contribute to the total response of BC sound, especially at the high frequencies, although current models of the cochlea assume a rigid OSL. The measurements reported here can be used to include a flexible OSL in cochlear models.
Alfred L Nuttall - One of the best experts on this subject based on the ideXlab platform.
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minimal Basilar Membrane motion in low frequency hearing
Proceedings of the National Academy of Sciences of the United States of America, 2016Co-Authors: Rebecca L. Warren, Tobias Reichenbach, Steven L Jacques, Ruikang K Wang, Sripriya Ramamoorthy, Nikola Ciganovic, Yuan Zhang, Teresa Wilson, Tracy Petrie, Alfred L NuttallAbstract:Low-frequency hearing is critically important for speech and music perception, but no mechanical measurements have previously been available from inner ears with intact low-frequency parts. These regions of the cochlea may function in ways different from the extensively studied high-frequency regions, where the sensory outer hair cells produce force that greatly increases the sound-evoked vibrations of the Basilar Membrane. We used laser interferometry in vitro and optical coherence tomography in vivo to study the low-frequency part of the guinea pig cochlea, and found that sound stimulation caused motion of a minimal portion of the Basilar Membrane. Outside the region of peak movement, an exponential decline in motion amplitude occurred across the Basilar Membrane. The moving region had different dependence on stimulus frequency than the vibrations measured near the mechanosensitive stereocilia. This behavior differs substantially from the behavior found in the extensively studied high-frequency regions of the cochlea.
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in vivo measurement of amplifying motion within the organ of corti under sound stimulation using optical coherence tomography
Proceedings of SPIE, 2012Co-Authors: Niloy Choudhury, Anders Fridberger, Fangyi Chen, Dingjun Zha, Jiefu Zheng, Steven L Jacques, Ruikang K Wang, Alfred L NuttallAbstract:Hearing in mammals, depend on an amplifying motion which hypothetically uses force from outer hair cells (OHC) motility to enhance sound induced vibration of the organ of Corti of cochlea. In this hypothesis the differential motion among key structures in this organ and the timing of the OHC force generation is essential for cochlear amplification to occur. Using a time domain optical coherence tomography system which allows us to make vibration measurements we were able to measure differential motion of two functionally important surfaces, namely, Basilar Membrane and reticular lamina. The reticular lamina vibrates at higher amplitude than the Basilar Membrane and has significant phase lead over Basilar Membrane vibration. The differential motion, that is, different amplitude and phase of vibration, become less as the energy of the sound stimulus is increased and the amplification processes in the organ of Corti are quenched.
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alterations of Basilar Membrane response phase and velocity after acoustic overstimulation
Hearing Research, 2002Co-Authors: Anders Fridberger, Alfred L Nuttall, Jiefu ZhengAbstract:To investigate the physiology of noise-induced hearing loss, the sound-induced vibrations of the Basilar Membrane (BM) of the inner ear were measured in living anesthetized guinea pigs before and after intense sound exposure. The vibrations were measured using a laser Doppler velocimeter after placing reflective glass beads on the BM. Pseudo-random noise waveforms containing frequencies between 4 and 24 kHz were used to generate velocity tuning curves. Before overstimulation, sharp response peaks were seen at stimulus frequencies between 15 and 17 kHz, consistent with the expected best frequency of the recording location. The response to low level stimuli lagged the high level ones by up to 90° at the characteristic frequency. Following exposure to loud sound, the BM vibrations showed a pronounced reduction in amplitude, primarily at low stimulus levels, and the best frequency moved to approximately 12 kHz. At higher levels, the reduction was either absent or much smaller. In addition to the amplitude changes, increased phase lags were seen at frequencies near the characteristic frequency. In animals with more severe exposures, response phases were altered also at frequencies showing no change of the amplitude. The phase was independent of stimulus level after severe exposures.
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Steady-state sinusoidal velocity responses of the Basilar Membrane in guinea pig.
The Journal of the Acoustical Society of America, 1996Co-Authors: Alfred L Nuttall, D F DolanAbstract:This report provides a detailed analysis of tone-evoked velocity responses of Basilar Membrane (BM) motion measured in the basal turn of the guinea pig cochlea. A laser Doppler vibrometer, coupled to a compound microscope, measured the velocity of reflective microbeads placed onto the scala tympani surface of the BM. The velocity responses of the stapes footplate were also determined, allowing the calculation of a BM transfer function. The normal transfer function is compared to that seen with cochlear "insensitivity" and postmortem. This comparison results in measures of the active process contribution to the magnitude and phase of the BM transfer function. It was found that the active process contributed as much as 65 dB of "gain" and 270 degrees of phase lag at the best frequency. Other details about features of input/output velocity functions and the derived mechanical frequency-tuning curve at a criterion of 50 micron/s are analyzed.
Mario A. Ruggero - One of the best experts on this subject based on the ideXlab platform.
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delays of stimulus frequency otoacoustic emissions and cochlear vibrations contradict the theory of coherent reflection filtering
Journal of the Acoustical Society of America, 2005Co-Authors: Jonathan H Siegel, A N Temchin, Amanda J Cerka, Alberto Reciospinoso, Pim Van Dijk, Mario A. RuggeroAbstract:When stimulated by tones, the ear appears to emit tones of its own, stimulus-frequency otoacoustic emissions (SFOAEs). SFOAEs were measured in 17 chinchillas and their group delays were compared with a place map of Basilar-Membrane vibration group delays measured at the characteristic frequency. The map is based on Wiener-kernel analysis of responses to noise of auditory-nerve fibers corroborated by measurements of vibrations at several Basilar-Membrane sites. SFOAE group delays were similar to, or shorter than, Basilar-Membrane group delays for frequencies >4 kHz and <4 kHz, respectively. Such short delays contradict the generally accepted "theory of coherent reflection filtering" [Zweig and Shera, J. Acoust. Soc. Am. 98, 2018-2047 (1995)], which predicts that the group delays of SFOAEs evoked by low-level tones approximately equal twice the Basilar-Membrane group delays. The results for frequencies higher than 4 kHz are compatible with hypotheses of SFOAE propagation to the stapes via acoustic waves or fluid coupling, or via reverse Basilar Membrane traveling waves with speeds corresponding to the signal-front delays, rather than the group delays, of the forward waves. The results for frequencies lower than 4 kHz cannot be explained by hypotheses based on waves propagating to and from their characteristic places in the cochlea.
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mechanical bases of frequency tuning and neural excitation at the base of the cochlea comparison of Basilar Membrane vibrations and auditory nerve fiber responses in chinchilla
Proceedings of the National Academy of Sciences of the United States of America, 2000Co-Authors: Mario A. Ruggero, A N Temchin, Shyamla S Narayan, Alberto RecioAbstract:We review the mechanical origin of auditory-nerve excitation, focusing on comparisons of the magnitudes and phases of Basilar-Membrane (BM) vibrations and auditory-nerve fiber responses to tones at a basal site of the chinchilla cochlea with characteristic frequency approximately 9 kHz located 3.5 mm from the oval window. At this location, characteristic frequency thresholds of fibers with high spontaneous activity correspond to magnitudes of BM displacement or velocity in the order of 1 nm or 50 microm/s. Over a wide range of stimulus frequencies, neural thresholds are not determined solely by BM displacement but rather by a function of both displacement and velocity. Near-threshold, auditory-nerve responses to low-frequency tones are synchronous with peak BM velocity toward scala tympani but at 80-90 dB sound pressure level (in decibels relative to 20 microPascals) and at 100-110 dB sound pressure level responses undergo two large phase shifts approaching 180 degrees. These drastic phase changes have no counterparts in BM vibrations. Thus, although at threshold levels the encoding of BM vibrations into spike trains appears to involve only relatively minor signal transformations, the polarity of auditory-nerve responses does not conform with traditional views of how BM vibrations are transmitted to the inner hair cells. The response polarity at threshold levels, as well as the intensity-dependent phase changes, apparently reflect micromechanical interactions between the organ of Corti, the tectorial Membrane and the subtectorial fluid, and/or electrical and synaptic processes at the inner hair cells.
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Frequency Tuning of Basilar Membrane and Auditory Nerve Fibers in the Same Cochleae
Science (New York N.Y.), 1998Co-Authors: S S Narayan, A N Temchin, Alberto Recio, Mario A. RuggeroAbstract:Responses to tones of a Basilar Membrane site and of auditory nerve fibers innervating neighboring inner hair cells were recorded in the same cochleae in chinchillas. At near-threshold stimulus levels, the frequency tuning of auditory nerve fibers closely paralleled that of Basilar Membrane displacement modified by high-pass filtering, indicating that only relatively minor signal transformations intervene between mechanical vibration and auditory nerve excitation. This finding establishes that cochlear frequency selectivity in chinchillas (and probably in mammals in general) is fully expressed in the vibrations of the Basilar Membrane and renders unnecessary additional (“second”) filters, such as those present in the hair cells of the cochleae of reptiles.
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Science, 1998Co-Authors: S S Narayan, A N Temchin, Alfredo Recio, Mario A. RuggeroAbstract:Responses to tones of a Basilar Membrane site and of auditory nerve fibers innervating neighboring inner hair cells were recorded in the same cochleae in chinchillas. At near-threshold stimulus levels, the frequency tuning of auditory nerve fibers closely paralleled that of Basilar Membrane displacement modified by high-pass filtering, indicating that only relatively minor signal transformations intervene between mechanical vibration and auditory nerve excitation. This finding establishes that cochlear frequency selectivity in chinchillas (and probably in mammals in general) is fully expressed in the vibrations of the Basilar Membrane and renders unnecessary additional ("second") filters, such as those present in the hair cells of the cochleae of reptiles.
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two tone distortion on the Basilar Membrane of the chinchilla cochlea
Journal of Neurophysiology, 1997Co-Authors: Luis Robles, Mario A. Ruggero, Nola C RichAbstract:Robles, Luis, Mario A. Ruggero, and Nola C. Rich. Two-tone distortion on the Basilar Membrane of the chinchilla cochlea. J. Neurophysiol. 77: 2385–2399, 1997. Basilar Membrane responses to pairs of...