From Laboratory to Clinic: A Large Scale Study of Distortion Product Otoacoustic Emissions in Ears with Normal Hearing and Ears with Hearing Loss

Within the limits related to the effects of primary frequency and audiometric criterion, it appears that DPOAE measurements can be used to accurately identify auditory status. An approach is described, using the present data set, that allows one to assign to any measured DPOAE value (DPOAE amplitudes, DPOAE/noise) the probability that the response is coming either from the distribution of normal or impaired responses. In addition, DPOAE/noise systematically decreases as hearing loss increases over the range of hearing losses from 0 to about 40 to 60 dB HL (depending on frequency), thus potentially enabling one to differentiate hearing losses over this range. For hearing losses greater than 50 to 60 dB HL, ears do not produce measurable DPOAEs and thus, no predictive relationship exists.