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.