Spontaneous Production Rates in Song and Speech

Abstract

Many everyday tasks appear to be performed at an optimal rate that differs between individuals but is consistent within individuals. These optimal rates are estimated using a participant's Spontaneous Production Rate (SPR), the rate at which an individual produces sequences of sounds in the absence of external tempo cues. A previous study that measured SPRs in speech and piano production found no association between SPRs across tasks, a result suggesting that domain-specific constraints determine optimal rates. The present study addressed whether this dissociation would remain when music and speech are produced with the same effector system: vocal production. Participants spoke short, well-known phrases and sang familiar children's songs on “da” to avoid memorization of words. SPRs were measured by the mean inter-onset interval (IOI) between successively produced syllables or tones and showed large individual differences. Results showed consistent SPRs within individuals within each domain (speaking or singing) as well as consistent SPRs across the speaking and singing conditions. These results align with theories of optimal rates based on energy efficiency arising from biomechanical constraints rather than domain-specific communication goals.