Effect of Head Position on Distortion Product Otoacoustic Emissions

Abstract

Abstract Objectives The study aimed to explore the impact of various head positions on the distortion product otoacoustic emissions (DPOAE) amplitudes, identifying the specific DPOAE frequencies showing the effect was also of interest. Materials and Methods DPOAEs were recorded from the right ears of 50 normal-hearing individuals in six head positions, supine, and five sitting positions (head erect, roll left, roll right, pitch backward, and pitch forward). DPOAEs were averaged and measured for their overall and frequency-specific amplitudes at 1 kHz, 1.5 kHz, 2 kHz, 3 kHz, 4 kHz, 6 kHz, and 8 kHz. Statistical Analysis To investigate the statistical significance of the observed mean differences, the data was tested using repeated measures of analysis of variance (ANOVA) following the Shapiro–Wilk normality test. The pair-wise comparison was tested using the Bonferroni post-hoc test and one-sided Bayesian paired sample t-test. Results The results of ANOVA revealed a significant main effect of head posture only at 1 kHz. The Bonferroni post-hoc test and one-sided Bayesian paired sample t-test results showed significantly higher DPOAE amplitude in the head erect compared to the supine position. There were no significant differences between other pairs of head postures. Conclusion Head posture is a trivial influencing factor of DPOAEs and hence, does not require consideration in interpreting DPOAEs.