Distribution Pattern of Cochlear Harmonics

Dallos, Peter; Sweetman, Richard H.

doi:10.1121/1.1911371

Cited by 22 publications

(5 citation statements)

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“…The results of several other electrophysiological investigations, furthermore, indicate that the distortion products in the cochlea are generated in the region of the basilar membrane which is most sensitive to the fundamental component of the sound (Dallos & Sweetman, 1969;Pfeiffer & Molnar, 1970). It is tempting, therefore, to suggest that the source of zf± -/ 2 is the non-linearity in the basilar membrane motion shown by Rhode (1971).…”

Section: N O N -L I N E a R I T Ymentioning

confidence: 99%

Coding of sounds in lower levels of the auditory system

Møller

1972

Quart. Rev. Biophys.

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The great number of investigations and advanced developments in neurophysiology and psychoacoustics during recent years have extensively increased our knowledge about the frequency analysis of simple sounds in the peripheral auditory system.New methods have facilitated quantitative measurements of the amplitude of the submicroscopic vibration of a narrow segment of the basilar membrane in anaesthetized animals at physiological sound intensities. The results of these studies have quantitatively confirmed the results of past studies by showing that the basilar membrane has a selectivity with regard to tone frequency. In addition to this, the recent studies have increased our knowledge about the finer details of vibration of the basilar membrane. At the lowest levels used in the recent investigations, i.e. about 70 dB SPL, the selectivity in the 7 kHz region of the basilar membrane was found to be greater than expected on the basis of extrapolation of older data. Moreover, the high frequency slope of the tuning curves of the basilar membrane was found to be particularly steep. The results of these recent studies, furthermore, showed that the basilar membrane vibrates in a non-linear way at intensities within the physiological range. This non-linearity results in a broadening of the selectivity curves of a narrow segment of the basilar membrane when the sound intensity is increased.Little is known as to how the motion of the basilar membrane is transformed to excitation of the cochlear sensory cells, i.e. the haircells. The excitation may be related to displacement, spatial differentiation or other transformations of the basilar membrane motion. Recording from the interior of mammalian haircells has so far been unsuccessful, and the neural excitatory process within the haircells in the cochlea is as yet practically unknown. Studies of the haircells in the lateral line organ of fish have provided fundamental knowledge about their excitation; since they in many respects resemble those in the mammalian cochlea, the results very probably can be applied to the excitatory process in the mammalian cochlea.

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Section: N O N -L I N E a R I T Ymentioning

confidence: 99%

Coding of sounds in lower levels of the auditory system

Møller

1972

Quart. Rev. Biophys.

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“…The acoustic analysis suggests the large harmonic distortions seen in the 45 Hz CR are generated by nonlinear mechanisms within the cochlea, as expected, and not simply responses to distortion in the acoustic stimulus. This experiment was originally performed by Dallos & Sweetman (1969) where input-output functions of OHCs with various characteristic frequencies were probed with pure tones and their harmonic components in order to prove nonlinearity of the hair cell response.…”

Section: Acoustic Analysismentioning

confidence: 99%

“…First, to confirm that the rich harmonic distortion in the low-frequency RW response was produced by nonlinear mechanisms in the cochlea, and was not simply due to distortions present in the acoustic stimulus. To test this hypothesis, we employ a strategy identical to what Dallos & Sweetman (1969) used to compare the spatial distribution of harmonics in the CM, in order to show that the generation of the harmonic components were not simply a response to acoustic distortion. Secondly, the sources of the low-frequency CR were estimated with an analytic model.…”

Section: Introductionmentioning

confidence: 99%

An analytic approach to identifying the sources of the low-frequency round window cochlear response

Kamerer

Chertoff

2019

Hearing Research

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The cochlear microphonic, traditionally thought of as an indication of electrical current flow through hair cells, in conjunction with suppressing high-pass noise or tones, is a promising method of assessing the health of outer hair cells at specific locations along the cochlear partition. We propose that the electrical potential recorded from the round window in gerbils in response to lowfrequency tones, which we call cochlear response (CR), contains significant responses from multiple cellular sources, which may expand its diagnostic purview. In this study, CR is measured in the gerbil and modeled to identify its contributing sources. CR was recorded via an electrode placed in the round window niche of sixteen Mongolian gerbils and elicited with a 45 Hz tone burst embedded in 18 high-pass filtered noise conditions to target responses from increasing regions along the cochlear partition. Possible sources were modeled using previously-published hair cell and auditory nerve response data, and then weighted and combined using linear regression to produce a model response that fits closely to the mean CR waveform. The significant contributing sources identified by the model are outer hair cells, inner hair cells, and the auditory nerve. We conclude that the low-frequency CR contains contributions from several cellular sources.

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“…Harmonic distortion of the CM is of two types: (i) the distortion due to a high (90 dB +) stimulus appears to occur by the generation of more longitudinal shear stresses (Tonndorf, 1958); i.e. the point along the cochlea of maximum partition vibration is different for the different frequency components, both of the fundamental, which is present in the stimulus, and of the harmonics, which are not present in the stimulus; and (2) the distortion due to moderately high (60 dB) stimulation appears due to radial shear stresses (Dallos & Sweetman, 1969;Worthington, 1970), i.e. the point along the cochlea of maximum partition vibration is approximately the same for the different frequency components, both for the fundamental which is present in the stimulus and for the harmonics which are not.…”

Section: Introductionmentioning

confidence: 99%

“…The fundamental, second and third harmonics are all plotted at the frequency of the fundamental. (FromDallos & Sweetman, 1969. )…”

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confidence: 99%

The transfer function of the cochlea

Barrett

1978

Quart. Rev. Biophys.

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A sinusoidal signal is generally considered the simplest auditory signal. It is, indeed, a simple signal. However, it does not follow that a complex analysing device, like the cochlea, should treat a simple signal in a simple way. Indeed, a simple signal may appear to be complex when viewed from the standpoint of the device considered. Such an observation becomes cogent when one is attempting to discover the analysing capabilities of a device such as the cochlea, which appears designed to handle signals more complex than a sinusoid or multiple sinusoids.

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Distribution Pattern of Cochlear Harmonics

Cited by 22 publications

References 1 publication

Coding of sounds in lower levels of the auditory system

Coding of sounds in lower levels of the auditory system

An analytic approach to identifying the sources of the low-frequency round window cochlear response

The transfer function of the cochlea

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