Auditory-Motor Synchronization and Perception Suggest Partially Distinct Time Scales in Speech and Music

Whether the different dominant rhythmic structure in speech (~4.5 Hz) and music (~2 Hz) emerges from distinct neural auditory or motor related mechanisms is debated. We provide a new perspective by investigating the effect of different articulator systems and their auditory-motor synchronization strength on rate-specific processing in both domains. A perception and a synchronization task involving speech and music stimuli and articulators (whispering, tapping), were conducted at slow and fast rates. Although synchronization performance was generally better at slow rates, the results suggest domain-specific rate preferences. Tapping was advantaged compared to whispering at slow but not at faster rates. Synchronization was domain-dependent at slow, but highly correlated across domains at faster rates. Perception of speech and music was optimal at different timescales, and predicted by the synchronization strength. Our data suggests partially independent mechanisms mediating an impact of the articulator system on the optimal time scales for speech and music.