Aural Acoustic StapediusMuscle Reflex Threshold P

Authors: Douglas H Keefe M Patrick Feeney Lisa L Hunter Denis F Fitzpatrick

Publish Date: 2016/12/12

Volume: 18, Issue: 1, Pages: 65-88

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Abstract

Powerbased procedures are described to measure acoustic stapediusmuscle reflex threshold and suprathreshold responses in human adult and infant ears at frequencies from 02 to 8 kHz The stimulus set included five clicks in which four pulsed activators were placed between each pair of clicks with each stimulus set separated from the next by 079 s to allow for reflex decay Each click response was used to detect the presence of reflex effects across frequency that were elicited by a pulsed broadbandnoise or tonal activator in the ipsilateral or contralateral test ear Acoustic reflex shifts were quantified in terms of the difference in absorbed sound power between the initial baseline click and the later four clicks in each set Acoustic reflex shifts were measured over a 40dB range of pulsed activators and the acoustic reflex threshold was objectively calculated using a maximum 10 likelihood procedure To illustrate the principles underlying these new reflex tests reflex shifts in absorbed sound power and absorbance are presented for data acquired in an adult ear with normal hearing and in two infant ears in the initial and followup newborn hearing screening exams one with normal hearing and the other with a conductive hearing loss The use of absorbed sound power was helpful in classifying an acoustic reflex shift as present or absent The resulting reflex tests are in use in a large study of wideband clinical diagnosis and monitoring of middleear and cochlear function in infant and adult earsThis research was supported by R01 grant DC010202 and P30 grant DC004662 awarded from the National Institute on Deafness and Other Communication Disorders The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or the Department of Veterans Affairs Douglas Keefe has an interest in the commercial development of devices to assess middleear function

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