Table of Contents

ABSTRACT

The auditory brainstem response (ABR) test has been used clinically for various applications. Nevertheless, in certain disorders, contradictory results are observed between studies. In view of this, employing complex stimulations in the ABR testing can be beneficial in detecting subtle brainstem problems as well as in assessing the function of binaural hearing. As such, the present study was conducted to compare the ABR results when stimulated by monaural and binaural stimulations in the presence of masking noise. In this cross-sectional study, 14 healthy adults (with a mean age of 27.2 ± 4.1 years) underwent the ABR testing with complex stimulations. The stimuli were custom-built clicks that were mixed with white noise (i.e., simultaneous mask-ing at 0 dB signal to noise ratio). The latencies of waves III and V were found to be significantly shorter in the binaural condition (p < 0.05). The binaural stimulation produced a statistically higher mean amplitude of wave V compared to the monaural condition (p < 0.001). To conclude, the desired effect of binaural hearing was evident, as the binaural stimulation produced ABR waveforms with statistically shorter latencies and higher amplitudes relative to the monaural stimulation. This complex ABR technique may have the potential to enhance the usefulness of ABR when testing patients with auditory brainstem dysfunctions. Keywords: Auditory brainstem response, binaural hearing, masking, click, amplitude, latency