Daylong Mobile Audio Recordings Reveal Multitimescale Dynamics in Infants’ Vocal Productions and Auditory Experiences

Abstract

The sounds of human infancy—baby babbling, adult talking, lullaby singing, and more—fluctuate over time. Infant-friendly wearable audio recorders can now capture very large quantities of these sounds throughout infants’ everyday lives at home. Here, we review recent discoveries about how infants’ soundscapes are organized over the course of a day. Analyses designed to detect patterns in infants’ daylong audio at multiple timescales have revealed that everyday vocalizations are clustered hierarchically in time, that vocal explorations are consistent with foraging dynamics, and that some musical tunes occur for much longer cumulative durations than others. This approach focusing on the multiscale distributions of sounds heard and produced by infants is providing new, fundamental insights on human communication development from a complex-systems perspective.