Towards the preferred stimulus parameters for distortion product otoacoustic emissions in adults: A preliminary study

BACKGROUND: Although distortion product otoacoustic emissions (DPOAEs) are useful in evaluating cochlear outer hair cell function, determining the optimal stimulus parameters could result in a more reliable, sensitive and specific diagnostic tool across the range of DPOAE applications. OBJECTIVES: To identify which stimulus parameters warrant further investigation for eliciting the largest and most reliable DPOAEs in adult humans. METHOD: A single group, repeated measures design involving a convenience sample of 20 normal-hearing participants between 19 and 24 years of age. RESULTS: Descriptive statistics and mixed model analyses suggested L(1)/L(2) intensity levels of 65/65 dB sound pressure level (SPL) and 65/55 dB SPL, and f(2)/f(1) ratios of 1.18, 1.20 and 1.22 elicited larger and more reliable DPOAEs in both ears. CONCLUSION: Further investigation of the 65/65 dB SPL and 65/55 dB SPL intensity levels and the 1.18, 1.20 and 1.22 f(2)/f(1) ratios is warranted to determine the stimulus parameters for eliciting the largest and most reliable DPOAEs in adult humans across the range of DPOAE applications.