Sensitization and Desensitization Effects in TEOAEs

Kim, Jinsook; Lee, Junghak

ORIGINAL ARTICLE

Commun Sci Disord. 1998;3(1): 84-104.

Jinsook Kim^` , and Junghak Lee^`

김진숙(Jinsook Kim)| 이정학(Junghak Lee)

ABSTRACT

Sensitization and desensitization effects in human transient evoked otoacoustic emissions (TEOAEs) were explored following exposure to brief pure tones. Their differential effects of frequencies, low, mid and high, and intensities, moderate and intense, were also carefully examined. Sixteen normal hearing young females, eight of them with one or more spontaneous otoacoustic emissions (SOAEs) and the other eight without SOAEs served as subjects. A repeated multivariate analysis of variance (MANOVA) was performed for statistical analysis. The general shape of the recovery pattern as a function of post - exposure time in TEOAEs demonstrated a sensitization effect between 20 seconds and 1 minute 40 seconds and a desensitization effect between 2 and 4 minutes. Both frequency and intensity of the exposure signal significantly differed in the magnitude and configuration of sensitization and desensitization. Depending on the exposure to pure tones, the time course was divided into the three types - the combination of sensitization and desensitization effects, only significant desensitization effect, and the initial sensitization effect. The characteristics and modalities of recovery pattern following the sound exposure are remarkably similar to the findings of behavioral sensitization and desensitization effects . This similarity suggests that in the nature of the motile activity of the cochlear partition, principally the outer hair cells are responsible for changes in OAEs and behavioral thresholds following the acoustic overstimulation. Additionally, the sensitivity of TEOAEs to intense sound exposure indicates that TEOAEs can be used for monitoring hearing changes following the sound exposure.