The aim of this study was to compare transiently evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE) in normal hearing ears (n = 44) and ears with cochlear hearing loss (HL) to obtain defined data on qualitative and quantitative correlations. In addition, we wanted to determine the reliability with which a clinical examiner could predict a typical, idealized audiometric configuration from TEOAE measurements. In the hearing-impaired subjects (n = 149), a 50% reduction of OAE incidence was caused by a mean HL of 10.5 dB for TEOAE compared to 27 dB SPL for DPOAE. A 90% incidence reduction was found at a mean threshold elevation of 33 dB for TEOAE and 51 dB for DPOAE. Correlation between TEOAE amplitudes and HL was in general rather low (r = –0.1 to –0.5), while DPOAE amplitudes showed a slightly better correlation with HL (r = –0.3 to –0.6). In general, efforts to derive an audiogram from evoked OAE have been more promising for DPOAE than for TEOAE. However, our studies showed that approximately 40% of the ears with HL could be categorized correctly into one of five typical audiometric patterns from TEOAE measurements. Additionally, a cochlear HL in or near the medium frequency range was much more likely to cause a reduction in TEOAE than an isolated low- or high-frequency lesion. Accordingly, TEOAE were often preserved in ears with isolated HL in the high or low frequencies.

Key words Otoacoustic emissions - Distortion product - emissions - Hearing loss - Audiometric configurations