Delayed auditory feedback and rhythmic tapping: evidence for a critical interval shift.

Delayed auditory feedback (DAF) impairs performance in speech, music, and tapping, with maximal impairment in speech occurring at a delay of about 200 msec. This critical interval has played a central role in many explanations of the DAF effect, including both closed-loop feedback explanations and alternative proposals. We investigated the nature of the critical interval in rhythmic tapping--in particular, whether the critical interval has a constant value or is dependent on performance rate. Three experiments in which a synchronization-continuation paradigm was used consistently showed that the critical interval shifted with different tapping rates, with maximal impairment occurring when the delay approximately equaled the tapping rate. We address the implications of these results for theories of DAF.