RESUMO
PURPOSE: The blood group can have an effect on the auditory system, and it is suggested that it could be an indicator of noise-induced hearing loss. There could be changes in the immittance findings, too, in adults having different blood groups. The present study attempted to determine if there are any differences in tympanometric results (admittance, peak pressure, gradient, resonance frequency, and ear canal volume) and acoustic reflex thresholds (ART) at 500, 1000, 2000 and 4000 Hz between individuals with different blood groups (A positive, B positive, O positive and AB positive). METHODS: Eighty normal hearing adults between the age of 18 and 27 years were considered for the study. They were divided into 20 participants, each with blood groups A, B, AB, and O. The immittance findings were recorded from all the participants of the study. RESULTS: The results showed that the resonance frequency was slightly higher in blood group O compared to other blood groups. Also, the acoustic reflex thresholds were slightly elevated at all frequencies (ipsilateral and contralateral) for individuals with blood group O. CONCLUSIONS: The results of the study suggest possible reduced outer hair cells in persons with blood group O. This could have resulted in elevated acoustic reflex thresholds.