Spontaneous Otoacoustic Emissions: A Non-Invasive Window Into Cochlear Mechanics


Wednesdays@NICO Seminar, Noon, January 31 2007, Chambers Hall, Lower Level

Prof. Sumitrajit Dhar, Northwestern University


The acute sensitivity and sharp frequency selectivity exhibited by the peripheral auditory system led Gold (1948) to speculate about an active element in cochlear mechanics which could generate sounds "if the feedback ever exceeded the losses". Kemp (1978) successfully recorded such signals by placing a sensitive microphone in the ear canal and otoacoustic emissions (OAEs) have since served as a promising tool for exploring cochlear mechanics. We will discuss current models of OAE generation and explore experimental results in support of these models. Our discussion will be based on spontaneous OAEs, which are generated in the cochlea without any external stimulation. Our recent work demonstrates dynamic elements of cochlear mechanics not reported before. We are also interested in developing clinical tools capable of detecting minor insults to cochlear physiology and will share recent results from our endeavors in that direction.