On ringing limits of the auditory periphery

Boer, E. de; Kruidenier, C.

doi:10.1007/bf00199575

Cited by 31 publications

(15 citation statements)

References 35 publications

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“…We surmise that the system properties that make such predictions possible are the same that severely restrict the prominence of basilar-membrane harmonic distortion and other nonlinearities, especially when stimulation is confined to a single spectral level (e.g., Evans, 1989;de Boer and Kruidenier, 1990;Zwislocki et al, 1997). (1) The magnitude-and phase-frequency spectra of responses to a given type of stimulus (click or tone) presented at any one level accurately predicts responses to the other type of stimulus only at a single, specific level.…”

Section: E Nonlinear Phase Shifts In Responses To Clicks and Their Rmentioning

confidence: 93%

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

Recio

Rich

Narayan

et al. 1998

The Journal of the Acoustical Society of America

166

165

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Basilar-membrane responses to clicks were measured, using laser velocimetry, at a site of the chinchilla cochlea located about 3.5 mm from the oval window (characteristic frequency or CF: typically 8-10 kHz). They consisted of relatively undamped oscillations with instantaneous frequency that increased rapidly (time constant: 200 µs) from a few kHz to CF. Such frequency modulation was evident regardless of stimulus level and was also present post-mortem. Responses grew linearly at low stimulus levels, but exhibited a compressive nonlinearity at higher levels. Velocity-intensity functions were almost linear near response onset but became nonlinear within 100 µs. Slopes could be as low as 0.1-0.2 dB/dB at later times. Hence, the response envelopes became increasingly skewed at higher stimulus levels, with their center of gravity shifting to earlier times. The phases of near-CF response components changed by nearly 180 degrees as a function of time. At high stimulus levels, this generated cancellation notches and phase jumps in the frequency spectra. With increases in click level, sharpness of tuning deteriorated and the spectral maximum shifted to lower frequencies. Response phases also changed as a function of increasing stimulus intensity, exhibiting relative lags and leads at frequencies somewhat lower and higher than CF, respectively. In most respects, the magnitude and phase frequency spectra of responses to clicks closely resembled those of responses to tones. Post-mortem responses were similar to in vivo responses to very intense clicks.

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Section: E Nonlinear Phase Shifts In Responses To Clicks and Their Rmentioning

confidence: 93%

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

Recio

Rich

Narayan

et al. 1998

The Journal of the Acoustical Society of America

166

165

View full text Add to dashboard Cite

show abstract

“…To investigate the possible role of within-channel effects in CDD, we simulated the output of an auditory filter centered at the target frequency, using a gammatone filter with an equivalent rectangular bandwidth of 230 Hz (Moore et al, 1989;Patterson and Cutler, 1989;de Boer and Kruidenier, 1990). We started by generating samples of noise in the same way as described above (under methods, experiment 1).…”

Section: Within-channel Effects In Cddmentioning

confidence: 99%

Profile analysis and comodulation detection differences using narrow bands of noise and their relation to comodulation masking release

Fantini

Moore

1994

The Journal of the Acoustical Society of America

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Experiment 1 examined the ability to compare relative level across frequency (profile analysis) for stimuli that were dynamically varying over time. The task was to detect an increment in level of a narrow band of noise (the target) in the presence or absence (reference condition) of four flanking bands (FBs). The envelopes of the FBs were either the same as that of the target (correlated condition), independent of that of the target but the same as each other (co-uncorrelated condition), or all independent (all-uncorrelated condition). The overall level of the stimuli was either fixed or randomly varied from one stimulus to the next. The results showed that subjects can make effective use of spectral-shape cues even for stimuli whose amplitudes vary markedly over time. In the correlated condition, the threshold for detecting an increment in the level of the target band was decreased (relative to the reference condition) both when the overall level was fixed and when it was varied randomly from stimulus to stimulus. In the uncorrelated conditions, the FBs did not lead to better performance when the overall level was fixed; rather they produced a small interference effect. When the overall level was randomized, the presence of uncorrelated FBs produced thresholds that decreased with increasing bandwidth and, for a bandwidth of 64 Hz, produced an improvement in performance (relative to the reference condition) that was almost as large as that produced by the correlated FBs. It seems that the more rapid fluctuations in the wider bands of noise were smoothed by the auditory system, enabling information about the long-term spectral shape to be extracted effectively. Experiment 2 used similar stimuli, but the task was to detect the target, rather than to discriminate its level. Detection thresholds in the presence of FBs were lowest in the co-uncorrelated condition, higher in the correlated condition, and highest in the all-uncorrelated condition. Thus the presence of correlated FBs improved discrimination thresholds in the profile analysis task, but impaired performance in the detection task. Reasons for the discrepancy between the effects of correlated FBs in the two tasks are discussed in the context of the cues available to the listener.

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“…Simple second-order resonators – harmonic oscillators – do have limitations [119], [120] and at some stage it will be necessary to consider higher order systems with dispersion and nonlinearities, particularly for DPOAEs [12], [40]. However, it is possible to show that every nonlinear model can be given a linear equivalent [132], and it is in many ways remarkable that parallel-based models can give results fairly similar to serial-based equivalents.…”

Section: Resultsmentioning

confidence: 99%

“…In earlier work by this author [119], [120], revcor functions were fitted to cochlear nerve data and it was found that the delays, after accounting for synaptic delays, were measurable in microseconds. As an elaboration, the 1989 paper also measured the order of the equivalent filters and found that the order required was at least 2 (that of a simple mass–spring system) but sometimes higher (4 or even 10 at high frequencies), meaning that at the level of the nerve a simple resonator is an oversimplification and a higher-order filter may be necessary.…”

Section: Discussionmentioning

confidence: 99%

A Resonance Approach to Cochlear Mechanics

Bell

2012

PLoS ONE

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BackgroundHow does the cochlea analyse sound into its component frequencies? In the 1850s Helmholtz thought it occurred by resonance, whereas a century later Békésy's work indicated a travelling wave. The latter answer seemed to settle the question, but with the discovery in 1978 that the cochlea emits sound, the mechanics of the cochlea was back on the drawing board. Recent studies have raised questions about whether the travelling wave, as currently understood, is adequate to explain observations.ApproachApplying basic resonance principles, this paper revisits the question. A graded bank of harmonic oscillators with cochlear-like frequencies and quality factors is simultaneously excited, and it is found that resonance gives rise to similar frequency responses, group delays, and travelling wave velocities as observed by experiment. The overall effect of the group delay gradient is to produce a decelerating wave of peak displacement moving from base to apex at characteristic travelling wave speeds. The extensive literature on chains of coupled oscillators is considered, and the occurrence of travelling waves, pseudowaves, phase plateaus, and forced resonance in such systems is noted.Conclusion and significanceThis alternative approach to cochlear mechanics shows that a travelling wave can simply arise as an apparently moving amplitude peak which passes along a bank of resonators without carrying energy. This highlights the possible role of the fast pressure wave and indicates how phase delays and group delays of a set of driven harmonic oscillators can generate an apparent travelling wave. It is possible to view the cochlea as a chain of globally forced coupled oscillators, and this model incorporates fundamental aspects of both the resonance and travelling wave theories.

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On ringing limits of the auditory periphery

Cited by 31 publications

References 35 publications

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

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

Profile analysis and comodulation detection differences using narrow bands of noise and their relation to comodulation masking release

A Resonance Approach to Cochlear Mechanics

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