Auditory cortical and brainstem response dynamics in quiet and noise amongst unilaterally deaf adults with and without tinnitus
Year: 2025
Type: article
Abstract: • Cortical auditory evoked potential (CAEP) of the unilaterally deaf (UD) with tinnitus was determined by signal to noise ratio. • CAEP from the UD without tinnitus was determined by both stimulus level and signal to noise ratio. • Wave V was determined by stimulus level and signal to noise ratio for all groups. Cortical auditory evoked potentials (CAEPs) and Auditory Brainstem Responses (ABRs) elicited by sounds in quiet and in noise were compared between unilaterally deaf adults with and without associated tinnitus (UD+T and UD-T). CAEP amplitudes were hypothesised to primarily vary with absolute stimulus levels in UD+T listeners rather than signal-to-noise ratio (SNR), whereas ABR amplitudes would reflect both level and SNR regardless of tinnitus status. Responses were recorded at 60 and 45 dB nHL with white noise set to give 0 and +10 dB SNR. Participants were 8 UD-T, 13 UD+T listeners, and 13 binaurally hearing controls. The UD-T group CAEP amplitudes showed an additive effect of stimulus level (p = 0.025) and SNR (p = 0.002) while UD+T and control listeners showed only the effect of SNR (p = 0.004). ABR amplitudes reflected the additive effects of level and SNR in all groups. The primary determinant of CAEP amplitudes to signals in noise is SNR not stimulus level. This effect was not apparent in UD-T listeners, whose amplitudes were determined by both level and SNR, similarly to the brainstem potentials. The findings suggest altered processing of neural noise in unilaterally deaf adult listeners without tinnitus.
Source: Clinical Neurophysiology
Language: English
Subfield: Sensory Systems
Field: Neuroscience
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,790
Funder: University of Canterbury
OpenAlex ID: W4408058749