[The influence of contralateral acoustic stimulation on distortion products]

The suppressor effect of contralateral broad-band white noise stimulation at 60 dB SPL on distortion-product otoacoustic emissions (DPOAEs) from 40 human ears was examined. The sample was composed of 9 females and 11 males, age 21-28 years. All the ears had DPOAEs. The 2-6 kHz bands had an incidence of 100%, but 0.7 kHz was found in only 27%. Eighty-eight percent of the frequency points recorded had an amplitude of more than 3 dB SPL over background noise. Nevertheless, DPOAE amplitude decreased for frequencial bands 1 to 6 kHz when contralateral acoustic stimulation was employed. However, these differences were only statistically significant for 1.5, 2 and 3 kHz frequencies. No significant differences were found between the ears of a subject or between sexes.