The role of binaural input in music perception: Evidence from adults with single-sided deafness.
Single-sided deafness (SSD) is characterized by unilateral auditory deprivation, which disrupts binaural hearing. This study aimed to evaluate music perception in adults with SSD using behavioral measures and subjective ratings. Thirty adults with SSD were compared with 54 normal-hearing (NH) listeners tested under binaural (NH-B, n = 27) and simulated acute monaural (NH-M, n = 27) conditions in a free-field setup. Behavioral music perception was assessed using the Clinical Assessment of Music Perception (CAMP) battery, including Pitch Direction Discrimination (PDD), Timbre Recognition (TR), and Melody Recognition (MR). Temporal and spectral resolution were evaluated using the Adaptive Gap Detection Test (AGDT) and the Spectral-Temporally Modulated Ripple Test (SMRT). Participants also completed subjective ratings of music experience. After adjusting for age and pure-tone average, the SSD group performed significantly worse than the NH-B group on all five behavioral measures (PDD, TR, MR, AGDT, SMRT). Compared with NH-M, SSD performance was significantly poorer on PDD, MR, and AGDT, but did not differ significantly on TR or SMRT. NH-M and NH-B differed significantly on TR, MR, AGDT, and SMRT, but not on PDD. Individuals with SSD reported reduced music enjoyment, lower perceived sound quality, increased listening effort, poorer lyrics comprehension, and less frequent music listening than NH participants. Music perception in SSD appears to be multidimensionally affected. Although some performance patterns in SSD resemble acute monaural listening, more pronounced difficulties in pitch discrimination, melody recognition, and temporal resolution were observed beyond what monaural listening alone could account for, potentially reflecting additional factors associated with chronic unilateral hearing loss. These findings highlight the importance of binaural input for complex auditory processing and the relevance of evaluating music-related listening outcomes in SSD.