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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(More)
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 microseconds) from a few(More)
1. The vibratory response to two-tone stimuli was measured in the basilar membrane of the chinchilla cochlea by means of the Mössbauer technique or laser velocimetry. Measurements were made at sites with characteristic frequency (CF, the frequency at which an auditory structure is most sensitive) of 7-10 kHz, located approximately 3.5 mm from the oval(More)
A widely held hypothesis of mammalian cochlear function is that the mechanical responses to sound of the basilar membrane depend on transduction by the outer hair cells. We have tested this hypothesis by studying the effect upon basilar membrane vibrations (measured by means of either the Mössbauer technique or Doppler-shift laser velocimetry) of systemic(More)
1. The phase of excitation of inner hair cells (IHCs) relative to basilar membrane motion has been estimated as a function of best frequency (BF) (or, equivalently, cochlear location) by recording responses to tones (100-1,000 Hz) from chinchilla cochlear afferent axons at their central exit from the internal auditory meatus. 2. The time of IHC excitation(More)
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(More)
Basilar membrane (BM) velocity was measured at a site 3.5 mm from the basal end of the chinchilla cochlea using the Mössbauer technique. The threshold of the compound action potential recorded at the round window in response to tone bursts was used as an indicator of the physiological state of the cochlea. The BM input-output functions display a compressive(More)
The region of cerebral cortex in the owl monkey that is responsive to acoustic stimulation is located on the dorsal and lateral surfaces of the rostral half of the superior temporal gyrus. Systematic microelectrode mapping of this area has revealed multiple frequency representations. The boundaries of these fields determined electrophysiologically correlate(More)
When humans listen to pairs of thnes they hear additional tones, or distortion products, that are not present in the stimulus. Two-tone distortion products are also known as combination tones, because their pitches match combinations of the primary frequencies (f1 and f2, f2 greater than f1), such as f2-f1, (n + 1)f1-nf2 and (n + 1)f2-nf1 (n = 1, 2, 3...).(More)