[Study on distortion product otoacoustic emissions and expanded high frequency audiometry in noise exposure workers].

OBJECTIVE: To analyse the relationship of distortion product otoacoustic emissions(DPOAE), conventional pure tone audiometry and expanded high frequency audiometry, and discuss the originated mechanism of DPOAE and value in early diagnosis and detection noise-induced deafness. METHOD: DPOAE, conventional pure tone audiometry and expanded high frequency audiometry were performed in 42 young adults with normal hearing of control group and 20 noise exposure workers of test group. DPOAE amplitudes, conventional pure tone hearing thresholds and expanded high frequency hearing thresholds were compared. RESULT: In noise exposure workers against young adults with normal hearing, the pure tone hearing thresholds at 6.0 kHz and expanded high frequency area declined significantly(P < 0.05), DPOAE amplitudes at frequency from 4.0 to 6.0 kHz and 11.2 kHz declined significantly too(P < 0.05), but there existed no significantly difference at frequency from 12.5 to 16.0 kHz between the two groups(P > 0.05). CONCLUSION: DPOAE is potential implement to early diagnose and detect noise-induced deafness. It seems likely that the origination of DPOAE not limited to the outer hair cell in corresponding cochlear area. The originated area and mechanism of DPOAE should be solved by further studies.