Binaural interaction component in adults with normal hearing

OBJECTIVE: This study aimed to identify the binaural interaction component in adults with normal hearing through the use of the Auditory Brainstem Response (ABR). METHODS: A cross-sectional, observational, quantitative study was conducted at a philanthropic hospital specialized in Otorhinolaryngology and Speech-Language Pathology, located in Real Hospital Português de Beneficência em Pernambuco. The study was approved by the Research Ethics Committee (approval nº 6.203.668). The sample consisted of 20 adults, aged 19-52 years, of both sexes, with normal hearing. Participants underwent auditory brainstem response testing to calculate the binaural interaction component. Stimuli were presented in the following sequence: right monaural, left monaural, and then binaural stimulation. Descriptive analysis was performed using the mean of the recorded potentials. The binaural response was calculated by subtracting the sum of the monaural responses from the binaural response for each potential. Inferential analysis was conducted using the Mann-Whitney U test. RESULTS: The binaural interaction component was observed in all waves of the auditory brainstem response, with more consistent findings in wave V. No significant statistical differences were found when correlating the results with the studied variables. However, a trend was observed toward reduced wave amplitudes with increasing age. CONCLUSION: Adults with normal hearing present the binaural interaction component, as demonstrated through auditory brainstem response testing. LEVEL OF EVIDENCE: Level 4.