Confirmation of transiently evoked otoacoustic emissions based on user-independent criteria.

Transiently evoked otoacoustic emissions (TEOAEs) were recorded from 525 ears (children, 3-11 years). Based on visual evaluation, the recordings were classified as TEOAEs present, absent or uncertain. Within each group the distribution of response level and reproducibility as well as of four derived parameters were calculated. The latter comprised: (1) corrected response level (difference between response level and approximated noise), (2) weighted response level (product of response level and correlation), (3) weighted sound pressure of the response (product of sound pressure and correlation) and (4) level of the weighted sound pressure of the response (weighted sound pressure of the response transformed to decibels). Based on these distributions, criteria to separate recordings with TEOAEs from recordings without TEOAEs were established. In this study the cutoff point is the parameter value where the amount of incorrectly identified recordings with TEOAEs is equal to the amount of correctly identified recordings without TEOAEs. The corresponding limiting values are: (a) response level 7.3 dB with 7.6% incorrect identifications for each group, (b) reproducibility 56% with 4.2% incorrect identifications, (c) corrected response level 2.4 dB with 5% incorrect identifications, (d) weighted response level 3.7 dB with 3.2% of incorrect identifications, (e) sound pressure of the response 0.027 mPa with 2% incorrect identifications and (f) level of the weighted sound pressure of the response 1.22 dB with 2% incorrect identifications.