Double Dichotic Digit Test Performance of Professional Orchestra Musicians and Professional Choir Singers of Teatro alla Scala

Background/Objectives: While the “musician advantage” in auditory processing is well documented, how instrumentalists and singers differ in processing binaural input during dichotic listening tasks remains largely unexplored. This study aims to compare performance on the double dichotic digit test (double DDT) between orchestra professional musicians (OP) and professional choir singers (PCS). Methods: A comprehensive audiological battery and the Italian version of the double DDT were administered to 165 right-handed professional musicians (91 OP, 74 PCS) from Teatro alla Scala. Results: In both groups, right ear double DDT performances were significantly higher than those of the left ear (the Right Ear Advantage) (in PCS; p = 0.002, effect size = 0.241 and in OP; p < 0.001, effect size = 0.322). In the non-adjusted Mann–Whitney U test, the OP group’s double DDT right ear performance was significantly better than that of the PCS group (p = 0.023, effect size = 0.177). The DDT left ear performance (p = 0.102) and right ear advantage (p = 0.835) values of the OP group were similar to those of the PCS group. However, the adjusted Generalized Linear Models showed that the right (p = 0.005) and left ear (p = 0.038) double DDT performances of the PCS group were significantly lower than those of the OP group; this finding was not observed in the double DDT right ear advantage value (p = 0.92). Conclusions: In the OP group, dichotic listening function is bilaterally better than in the PCS group. It may be considered that these findings in the OP group could stem from the multimodal nature of playing an instrument, which integrates motor, visual, and auditory systems.