Comparison of 2f1-f2 DPOAE and 2f2-f1 DPOAE fine structure in young and middle-aged adults

Abstract

Objective: The 2f2-f1 DPOAE is not as popular as the 2f1-f2 DPOAE in the clinical realm as it is not as robust. However, it does have an advantage of being a predominantly reflection emission. The reflection component has been found to be sensitive to cochlear damage. Our objective was to compare the two types of DPOAE to track subtle changes due to aging. Design: We used the most suitable stimulus parameters to record the fine structures of 2f2-f1 DPOAE and 2f1-f2 DPOAE for comparison in two groups of individuals. Study sample: Young adults and middle-aged adults with normal hearing sensitivity participated in the experiment. Both ears of all participants were tested. Results: Although reductions were noted in the both types of DPOAE in the middle-aged participants compared with the young adults, the decrease in amplitude of the 2f2-f1 DPOAE was found to be statistically significant. This corresponded with statistically significant reductions in the reflection component of the 2f1-f2 DPOAE. Reductions in the 2f2-f1 DPOAE were found with both, high-level and low-level primaries. Conclusions: These results highlight the advantages of analysing fine structure data of the 2f2-f1 DPOAE to track subtle cochlear changes in response to aging.

Key Words::

• Distortion product otoacoustic emissions
• generator and reflections components
• fine structure
• aging

Acknowledgements

This work was completed when all three authors were associated with the University of Minnesota. We would like to thank Dr. Edward Carney for help with statistical analysis. Thanks are due to Dr. Sumit Dhar for helpful discussions, and to Dr. Robert Schlauch for extensive comments on the manuscript. We also thank Tess Koerner for editing the manuscript. We are grateful to Dr. Talmadge and to Dr. Glenis Long for providing the software used in data collection and analysis. Financial support received from the University of Minnesota and the American Speech-Language-Hearing Association is gratefully acknowledged. Portions of this work were presented at the annual conventions of the American Academy of Audiology (2010) and the American Speech-Language-Hearing Association (2011).

Declaration of interest: The authors report no declarations of interest.