Efferent Auditory System Functioning and Speech Perception in Noise in Individuals with Type II Diabetes Mellitus

Objective: There could be efferent system damage in individuals with type II diabetes mellitus. The study attempts to determine the efferent auditory system functioning through contralateral suppression of otoacoustic emissions (OAE) and speech perception in noise (SPIN) in individuals with type II diabetes mellitus (DM). Method: The study was carried out on twenty five participants (50 ears) with type II DM patients who were diagnosed by an endocrinologist and twenty five healthy age matched controls (50 ears) were included in the study. Contralateral suppression of OAE and SPIN were administered on both the groups and they were compared and correlated. Results: The results of the study show that individuals with type II DM had statistically significant lower contralateral suppression values and had poorer speech perception in noise. In addition, there were significant correlations between SPIN scores and the amount of suppression in individuals with type II DM. Conclusion: The individuals with DM showed difficulty understanding speech in presence of noise and that can be attributed to efferent system damage. Thus, contralateral suppression can be a useful marker in early diagnosis of cochleopathy and auditory efferent disorder. The present study can provide important evidence for early diagnosis and early treatment of diabetic complications.