Rhythm in speech and animal vocalizations: a cross‐species perspective

Abstract

Why does human speech have rhythm? As we cannot travel back in time to witness how speech developed its rhythmic properties and why humans have the cognitive skills to process them, we rely on alternative methods to find out. One powerful tool is the comparative approach: studying the presence or absence of cognitive/behavioral traits in other species to determine which traits are shared between species and which are recent human inventions. Vocalizations of many species exhibit temporal structure, but little is known about how these rhythmic structures evolved, are perceived and produced, their biological and developmental bases, and communicative functions. We review the literature on rhythm in speech and animal vocalizations as a first step toward understanding similarities and differences across species. We extend this review to quantitative techniques that are useful for computing rhythmic structure in acoustic sequences and hence facilitate cross‐species research. We report links between vocal perception and motor coordination and the differentiation of rhythm based on hierarchical temporal structure. While still far from a complete cross‐species perspective of speech rhythm, our review puts some pieces of the puzzle together.

Motor and Predictive Processes in Auditory Beat and Rhythm Perception

“…The role of the motor system in rhythm perception is most obviously recognized by examining how it is we engage our body with music. In addition to beat induction in passive music listening, humans -and a limited group of birds and mammals (Kotz et al, 2018;Ravignani et al, 2019) -can move in time to a musical beat. This process of rhythmic entrainment is defined as the ability to flexibly perceive and synchronize to the beat of music or other complex auditory rhythms.…”

Interactive rhythms across species: the evolutionary biology of animal chorusing and turn‐taking

“…A comparison between human and nonhuman interactive communication with a focus on rhythm is timely. 8,13,50,[54][55][56] However, at this early stage of animal turn-taking research, one needs to be careful in deciding which human concepts can be applied across species. For instance, taking turns may be important because one party may not be able to attend to a second when it is itself signaling…”

Speech rhythm as naturally occurring and culturally transmitted behavioral patterns

“…Sci . issue, several papers focus on the developmental and evolutionary aspects of speech rhythm, including reviews by Ravignani et al ., Filippi et al ., and Fitch, whose discussions masterfully encompass both ontogenetic and phylogenetic views on the emergence of rhythmic patterns in speech. As speech capacity—the capacity for vocal communication—is putatively a prerequisite for developing a language faculty, studies on speech rhythm may cast some light on the mystery of language evolution in the human genus.…”

“…Rhythmic continuity across utterances found in typologically distinct languages is scarcely, if at all, modulated by cultural differences, suggesting strong universal influences on how rhythm is used to coordinate interlocutors’ utterances in live interactions . The evolutionary roots of this faculty are explored in the cross‐species study by Ravignani et al …”

“…30,[32][33][34] Rhythmic continuity across utterances found in typologically distinct languages is scarcely, if at all, modulated by cultural differences, suggesting strong universal influences on how rhythm is used to coordinate interlocutors' utterances in live interactions. 35 The evolutionary roots of this faculty are explored in the cross-species study by Ravignani et al 26 Acoustic and temporal characteristics inherent to different rhythms, especially the degree of temporal isochrony between salient acoustic events in vocal signals, have been associated with various affective states, affiliative and prosocial behaviors, and cooperative urges. 36,37 Corncrakes (a bird in the rail family), for example, switch from regular rhythm with isochronous intervocalization intervals to irregular rhythm when signaling aggression.…”