Spontaneous otoacoustic emissions in individuals with auditory neuropathy spectrum disorder

Objective: The objective of the study was to determine the prevalence of spontaneous otoacoustic emissions (SOAEs) in individuals with auditory neuropathy spectrum disorder (ANSD), and to examine the spectral distribution of the SOAE responses recorded compared with normal hearing individuals. Study design: SOAEs were recorded from 30 individuals with normal hearing and 30 individuals diagnosed as having auditory neuropathy spectrum disorder (ANSD). The recorded responses were analysed to determine the prevalence and spectral distribution of the SOAE responses from both the groups. Results and discussion: The prevalence of SOAEs in individuals with ANSD was higher than for normal hearing individuals; however, the difference was not statistically significant. Individuals with ANSD also exhibited a greater number multiple SOAEs than their normal counterparts, which is statistically significant. The SOAEs recorded from individuals with ANSD were mostly located in the lower frequency region, i.e. below 1500 Hz. On the other hand, many of the normal hearing individuals exhibited SOAEs more at higher frequencies, i.e. above 1500 Hz. Conclusion: The findings of the present study suggest that individuals with ANSD exhibit subtle abnormalities in the cochlea or medial olivocochlear system (MOCS).