Dynamics of real time DPOAE contralateral suppression in chinchillas and humans.
The dynamics of contralateral acoustic suppression were studied using real time (millisecond resolution) distortion product otoacoustic emissions (DPOAEs) in chinchillas and humans. Latency of DPOAE suppression onset is 26 ms in chinchillas and 45 ms in humans. After onset, suppression builds over time before tending to plateau, reflecting a temporal integration process with a time constant of 100 ms (chinchillas). In chinchillas, suppression persists for 40 ms even when elicited by stimuli as short as 5 ms. With stimuli >40 ms, offset and onset latencies are similar and duration of suppression equals that of the contralateral stimulus. A comparison of DPOAE suppression onset latency with neural latency data from the pathways involved suggests the following timing scheme: stimulus onset to activity in (ventral) cochlear nucleus, 4ms (15% of delay); transfer to olivocochlear efferents, 9 ms (35%); efferent conduction to presynaptic OHC site, 4ms (15%); synaptic and mechanical events at OHCs, 9 ms (35% of delay).
James
Adrian L
AL
Auditory Science Laboratory, Department of Otolaryngology and Brain and Behaviour Division, The Hospital for Sick Children, Toronto, Canada.
Harrison
Robert V
RV
Pienkowski
Martin
M
Dajani
Hilmi R
HR
Mount
Richard J
RJ
D000293:Adolescent; D000328:Adult; D000703:Analog-Digital Conversion; D000818:Animals; D001300:Audiometry, Evoked Response; D001306:Auditory Pathways / Q000502:physiology; D002682:Chinchilla; D003056:Cochlear Nerve / Q000502:physiology; D003199:Computer Systems; D004007:Dichotic Listening Tests; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D018072:Hair Cells, Auditory, Outer / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009433:Neural Inhibition / Q000502:physiology*; D009847:Olivary Nucleus / Q000502:physiology; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology*; D012016:Reference Values; D012815:Signal Processing, Computer-Assisted; D013045:Species Specificity