Basilar membrane measurements and the travelling wave

Johnstone, Brian M.; Patuzzi, Robert; Yates, Graeme K.

doi:10.1016/0378-5955(86)90090-0

Cited by 269 publications

(116 citation statements)

References 18 publications

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“…Some of our laboratory's publications noted in passing that velocity-intensity functions of chinchilla basilar-membrane responses to CF tones could approach linearity at high stimulus intensities (Ruggero and Rich, 1991b;Ruggero et al, 1992b;Ruggero et al, 1993). Such tendency toward linearization was rarely observed in Mössbauer experiments in normal cochleae (Sellick et al, 1982;Robles et al, 1986), but some authors argued for its existence on the basis of the effects of acoustic trauma (Patuzzi et al, 1984) and from theoretical considerations Johnstone et al, 1986;Patuzzi et al, 1989;Yates, 1990;Goldstein, 1995;Nobili and Mammano, 1996). The present investigation shows that within the range of intensities that are physiologically relevant (e.g., up to 100-110 dB) complete linearization does not occur in healthy cochleae.…”

Section: B Waveshape and Spectrum Of Basilar-membrane Responses To Tmentioning

confidence: 67%

“…The gain of the "cochlear amplifier"-There is widespread belief that something akin to an amplifier (Davis, 1983;Dallos, 1988Dallos, , 1992, active in healthy cochleae and presumably residing in the organ of Corti, is responsible for boosting the otherwise insensitive basilar-membrane responses of "passive" cochleae. One proposed method for measuring the gain of the cochlear amplifier is based on the presumption that responses to CF tones grow linearly at both low and high levels of stimulation (e.g., Johnstone et al, 1986;Patuzzi et al, 1989;Yates, 1990;Goldstein, 1995). The gain is defined as the difference between the sensitivities of responses to high-and low-level CF tones.…”

Section: B Waveshape and Spectrum Of Basilar-membrane Responses To Tmentioning

confidence: 99%

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Basilar-membrane responses to tones at the base of the chinchilla cochlea

Ruggero

Rich

Recio

et al. 1997

The Journal of the Acoustical Society of America

658

527

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Basilar-membrane responses to single tones were measured, using laser velocimetry, at a site of the chinchilla cochlea located 3.5 mm from its basal end. Responses to low-level (<10-20 dB SPL) characteristic-frequency (CF) tones (9-10 kHz) grow linearly with stimulus intensity and exhibit gains of 66-76 dB relative to stapes motion. At higher levels, CF responses grow monotonically at compressive rates, with input-output slopes as low as 0.2 dB/dB in the intensity range 40-80 dB. Compressive growth, which is significantly correlated with response sensitivity, is evident even at stimulus levels higher than 100 dB. Responses become rapidly linear as stimulus frequency departs from CF. As a result, at stimulus levels >80 dB the largest responses are elicited by tones with frequency about 0.4-0.5 octave below CF. For stimulus frequencies well above CF, responses stop decreasing with increasing frequency: A plateau is reached. The compressive growth of responses to tones with frequency near CF is accompanied by intensity-dependent phase shifts. Death abolishes all nonlinearities, reduces sensitivity at CF by as much as 60-81 dB, and causes a relative phase lead at CF.

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Section: B Waveshape and Spectrum Of Basilar-membrane Responses To Tmentioning

confidence: 67%

Section: B Waveshape and Spectrum Of Basilar-membrane Responses To Tmentioning

confidence: 99%

Basilar-membrane responses to tones at the base of the chinchilla cochlea

Ruggero

Rich

Recio

et al. 1997

The Journal of the Acoustical Society of America

658

527

View full text Add to dashboard Cite

show abstract

“…In comparable mammalian studies, such analysis revealed that the basilar membrane's sensitivity, tuning and nonlinearity depend on the physiological condition of the cochlea, and decreases or vanishes post-mortem (Rhode 1971;Sellick et al 1982;Johnstone et al 1986;reviewed by Ruggero 1992). We examined changes in sensitivity and tuning by measuring the £agellar mechanical response to identical random-noise stimuli before and just after the animal's death (¢gure 2a).…”

Section: Resultsmentioning

confidence: 99%

Active auditory mechanics in mosquitoes

Göpfert

Robert

2001

Proc. R. Soc. Lond. B

164

154

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In humans and other vertebrates, hearing is improved by active contractile properties of hair cells. Comparable active auditory mechanics is now demonstrated in insects. In mosquitoes, Johnston's organ transduces sound-induced vibrations of the antennal £agellum. A non-muscular`motor' activity enhances the sensitivity and tuning of the £agellar mechanical response in physiologically intact animals. This motor is capable of driving the £agellum autonomously, amplifying sound-induced vibrations at speci¢c frequencies and intensities. Motor-related electrical activity of Johnston's organ strongly suggests that mosquito hearing is improved by mechanoreceptor motility.

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“…In effect, we know much about how stimulation level influences BM response properties. With increasing level, the low-frequency tail of the frequency response at a fixed BM location grows linearly, while responses near the characteristic frequency ͑CF͒ grow less than linearly ͑Rhode, 1971; Johnstone et al, 1986;Ruggero et al, 1997͒. As a result, a sharply-tuned bandpass response at low levels gradually turns into a broadly tuned, more or less low-pass response as level increases.…”

Section: Introductionmentioning

confidence: 93%

Basilar-membrane responses to multicomponent (Schroeder-phase) signals: Understanding intensity effects

Summers

Boer

Nuttall

2003

The Journal of the Acoustical Society of America

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Harmonic complexes comprised of the same spectral components in either positive-Schroeder ͑ϩSchr͒ or negative-Schroeder ͑ϪSchr͒ phase ͓see Schroeder, IEEE Trans. Inf. Theory 16, 85-89 ͑1970͔͒ have identical long-term spectra and similar waveform envelopes. However, localized patterns of basilar-membrane ͑BM͒ excitation can be quite different in response to these two stimuli. Measurements in chinchillas showed more modulated ͑peakier͒ BM excitation for ϩSchr than ϪSchr complexes ͓Recio and Rhode, J. Acoust. Soc. Am. 108, 2281-2298 ͑2000͔͒. In the current study, laser velocimetry was used to examine BM responses at a location tuned to approximately 17 kHz in the basal turn of the guinea-pig cochlea, for ϩSchr and ϪSchr complexes with a 203-Hz fundamental frequency and including 101 equal-amplitude components from 2031 to 22 344 Hz. At 35-dB SPL, ϩSchr response waveforms showed greater amplitude modulation than ϪSchr responses. With increasing stimulation level, internal modulation decreased for both complexes. To understand the observed phenomena quantitatively, responses were predicted on the basis of a linearized model of the cochlea. Prediction was based on an ''indirect impulse response'' measured in the same animal. Response waveforms for Schroeder-phase signals were accurately predicted, provided that the level of the indirect impulse used in prediction closely matched the level of the Schroeder-phase stimulus. This result confirms that the underlying model, which originally was developed for noise stimuli, is valid for stimuli that produce completely different response waveforms. Moreover, it justifies explanation of cochlear filtering ͑i.e., differential treatment of different frequencies͒ in terms of a linear system.

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Basilar membrane measurements and the travelling wave

Cited by 269 publications

References 18 publications

Basilar-membrane responses to tones at the base of the chinchilla cochlea

Basilar-membrane responses to tones at the base of the chinchilla cochlea

Active auditory mechanics in mosquitoes

Basilar-membrane responses to multicomponent (Schroeder-phase) signals: Understanding intensity effects

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