Date of Graduation

Spring 2017

Degree

Doctor of Audiology

Department

Communication Sciences and Disorders

Committee Chair

Wafaa Kaf

Abstract

The recording of electrocochleography (ECochG) to tone burst stimuli with a high rate is hypothesized to provide advantages over standard click ECochG with slow rate. Specifically, the use of tone burst stimuli presented at a high rate may enhance the summating potential (SP) while also reducing neural contributions in the response. To allow for the analysis of the complex ECochG responses to high rates, the Continuous Loop Averaging Deconvolution (CLAD) technique was employed to deconvolve the responses. This study examined the effect of high rate and stimulus duration on the SP amplitude of tone burst extratympanic ECochG in 20 adult females with normal hearing. ECochG was recorded using 500 Hz and 2000 Hz stimuli with varied durations (12 ms, 6 ms, 3 ms) and five rates ranging from 7.1/s to 234.38/s. Within-subject repeated measures (rate x duration) analysis of variance were conducted. For both 500 Hz and 2000 Hz, the mean deconvolved SP amplitudes were larger at faster rates compared to slower rates, and larger at shorter duration than longer duration. With the long durations, the increase in SP amplitude with high rate is thought to be due to changes in cochlear mechanics and nonlinearity of the inner hair cells. However, the large amplitude measured in the short duration conditions is mostly due to the contribution of the action potential in the recording. Our study supports the use of the CLAD technique with tone burst ECochG and provides normative data upon which further research can build.

Keywords

electrocochleography, tone burst, summating potential, high repetition rate, Continuous Loop Averaging Deconvolution

Subject Categories

Communication Sciences and Disorders

Copyright

© Alana E. Kennedy

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Open Access

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