Cochlear reflectivity in transmission-line models and otoacoustic emission characteristic time delays.
In transmission-line models of cochlear mechanics, predictions about otoacoustic-emission delays depend on the place- or wave-fixed nature of the emission generation mechanism. In this work, transient evoked otoacoustic emissions (TEOAEs), recorded at different stimulus levels in 10 young subjects, were analyzed using wavelet-based time-frequency analysis to determine the latency of each frequency component of the response. The same wave forms were Fourier analyzed to evaluate the phase-gradient delay as a function of frequency. Interpreting the relation between these two characteristic delays using cochlear models shows that most of the TEOAE response can be attributed to place-fixed reflection mechanisms. The causality principle explains observed correlations between fluctuations of the TEOAE amplitude and phase-gradient delay.
Sisto
Renata
R
Dipartimento Igiene del Lavoro, ISPESL, Via Fontana Candida, 1, 00040 Monte Porzio Catone, Roma, Italy. r.sisto@dil.ispesl.it
Moleti
Arturo
A
Shera
Christopher A
CA
D000161:Acoustic Stimulation; D000328:Adult; D000465:Algorithms; D001307:Auditory Perception; D001696:Biomechanical Phenomena; D003051:Cochlea / Q000502:physiology*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D008954:Models, Biological; D017084:Otoacoustic Emissions, Spontaneous; D011930:Reaction Time; D012815:Signal Processing, Computer-Assisted; D013018:Sound Spectrography; D013997:Time Factors