The time-course of the effects of contralateral sound on the level of distortion product otoacoustic emissions

The effects of the addition of contralateral noise on the level of distorti on product otoacoustic emissions (DPOAEs) were examined. In the present stu dy, the DPOAEs were recorded for a relatively long period (2 minutes), and the time-course of the effects of contralateral sound on the level of DPOAE s were considered. In general, the addition of the contralateral noise resu lted in suppression of the level of DPOAEs. The time-course of this suppres sion appeared to depend on the level of the contralateral noise. When the l evel of the contralateral noise was low, the suppression of the level of DP OAEs seemed to be largely unchanged for at least 2 minutes. In contrast, wh en a relatively high level of contralateral noise was used, the suppression of the level of DPOAEs decreased with time, (C) 2000 Tohoku University Med ical Press.