The Effect of Middle Ear Effusion on Otoacoustic Emissions

Yeo, Sang Won; Park, Shi Nae; Youn, Sung Moon; Song, Chi Jun; Suh, Byung Do

Abstract

BACKGROUND AND OBJECTIVES: The transmission properties of the middle ear directly influence otoacoustic emissions (OAEs) which are transmitted from the cochlea to the ear canal via middle ear. The purpose of this study is to evaluate the effects of middle ear effusion (MEE) on detectability of various OAEs and to assess the potential applicability of DPOAE measurements in monitoring the middle ear status. MATERIALS AND METHOD: Spontaneous otoacoustic emissions (SOAEs), transiently evoked otoacoustic emissions (TEOAEs) and distortion product otoacoustic emissions (DPOAEs) were recorded for 44 normal ears and 32 ears with MEE. DPOAEs were collected in two basic forms consisting of distortion product audiograms(DPgrams) and input-output (I-O) functions, elicited by two primary tones fl and f2 with varying geometric mean frequencies between 1-6 kHz.
RESULTS
SOAEs were absent in 21 ears of 32 ears with MEE, TEOAEs were diminished in 28 ears with MEE, and DPgrams were eliminated in 17 ears with MEE. I-O function curves at 3 kHz and 4 kHz were significantly diminished by equal levels of fl and f2 primary tones of 45 & 55 dB SPL under the condition of MEE (p<0.05).
CONCLUSION
The results suggest that MEE affects the detectability of various OAEs and that the DP I-O function curve measurement at 3 and 4 kHz may be valuable to monitor the middle ear status in pediatric patients.