Rethinking the clinical utility of distortion-product otoacoustic emission (DPOAE) signal-to-noise ratio

Abstract

Objective

Distortion-product otoacoustic emission (DPOAE) levels are repeatable over time in normal-hearing individuals making DPOAE levels an ideal measurement for monitoring cochlear status in clinic and research applications. However, if DPOAE signal-to-noise ratio (SNR) values instead of levels are used for monitoring, the repeatability of this value needs to be established. This retrospective, cross-sectional study sought to determine DPOAE SNR repeatability in younger children, older children, young adults and a patient population with normal hearing.

Design

Each participant attended four sessions where DPOAE discrete frequency sweeps were collected at conventional (≤ 8 kHz) and/or extended-high frequencies (> 8 kHz). To examine the extent of variability to be expected for DPOAE SNR, average absolute SNR differences-between-trials were determined and compared to average absolute DPOAE level differences-between-trials.

Study samples

One hundred forty-five participants, incorporating four different groups from three different studies. Ages ranged from 3 to 55 years.

Results

Average SNR differences-between-trials across all frequencies are greater than differences for average DPOAE levels. Improved calibration methods result in SNR differences-between-trials that are similar across all frequencies

Conclusions

When monitoring cochlear health over an extended bandwidth, DPOAE levels are less variable across trials than SNR values, thus allowing earlier indicators of cochlear damage.

Keywords:

• Otoacoustic emissions
• distortion product otoacoustic emissions
• signal-to-noise ratio
• normal hearing
• monitoring
• calibration

Acknowledgements

We are grateful to Amanda Conrad and Shelli Newman for their contributions to this project. Special thanks to past and present members of the Auditory Physiology and Psychoacoustics Laboratory, for data collection and entry. We also thank the Mayo Clinic Department of Otolaryngology-Head and Neck Surgery Research Committee for their support. Heartfelt thanks to the research participants and patients who participated. Portions of this work were presented at the 36th and 37th American Auditory Society Meeting.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Work supported by the National Institutes of Health [DC008195 PI-Dreisbach] and The San Diego Foundation Blasker-Rose-Miah Fund [PI-Dreisbach].