Distortion product otoacoustic emissions: hit and false-positive rates in normal-hearing and hearing-impaired subjects.

OBJECTIVE

This study aimed to establish hit and false-positive rates for distortion product otoacoustic emissions (DPOAEs) using a commercial instrument.

STUDY DESIGN

This was a prospective study. The examiners performing the DPOAEs were blinded to pure-tone audiometric results. A decision matrix analysis was used to determine hit and false-positive rates for absolute amplitude, three amplitude-to-noise ratios, and three conditions that combined these two parameters.

SETTING

The study was performed at a tertiary care, outpatient clinical laboratory facility.

PATIENTS

Subjects with normal hearing and those with sensorineural hearing loss participated in the study.

MAIN OUTCOME MEASURES

Main outcome measures were hit and false-positive rates for various DPOAE measures.

RESULTS

Hit and false-positive rates were better for high than low frequencies. As absolute amplitude and amplitude-to-noise ratios increased hit and false-positive rates improved. Optimal hit rates generally exceeded 80%; false-positive rates were approximately 20% in the high-frequency range. Although the absolute amplitude measures seemed more useful than various ratio measures, there were advantages to using both parameters clinically.

CONCLUSIONS

DPOAEs have acceptable hit and false-positive rates for high frequencies but not for lower frequencies. DPOAE amplitude-to-noise ratios of +3 and even +6 dB may not be clinically feasible based on the current data. The overall findings obtained on the commercial instrument in this study compare favorably with previous studies of a similar nature.