Place-specific derived cochlear microphonics from human ears.
The high-pass noise masking technique was used to obtain derived frequency-specific cochlear microphonics (CM) from subtracted waveforms to rarefaction and condensation stimuli recorded with a tympanic membrane electrode. Two characteristics suggest that the response is place-specific CM: the derived response retains the same frequency as the stimulating toneburst and the response follows the stimulus polarity. For click stimulation, derived neural responses make the place-specific CM difficult to observe except in the 2-1 kHz derived band. In contrast, place-specific CM evoked by 0.5 and 1 kHz tonebursts can usually be detected in at least three derived bands. The amplitude of the response is largest in the derived band with center-frequency (CF) just above that of the toneburst. This discovery of a place-specific CM offers the possibility of assessing (outer) hair cell function in the apical part of the human cochlea.
Ponton
C W
CW
Electrophysiology Laboratory, House Ear Institute, Los Angeles, California.
Don
M
M
Eggermont
J J
JJ
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001300:Audiometry, Evoked Response; D003051:Cochlea / Q000502:physiology*; D003055:Cochlear Microphonic Potentials; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005260:Female; D006198:Hair Cells, Auditory / Q000502:physiology; D006309:Hearing / Q000502:physiology; D006311:Hearing Disorders / Q000175:diagnosis*; D006801:Humans; D008297:Male; D009622:Noise; D014432:Tympanic Membrane / Q000502:physiology