Sound and music: emotion tracks changes in the acoustic environment

Weiyi Maa and William Forde Thompsona, Human emotions track changes in the acoustic environment, Proceedings of the National Academy of Sciences, vol. 112 no. 47 > Weiyi Ma, 14563–14568, doi: 10.1073/pnas.1515087112

Significance

Emotions function to optimize adaptive responses to biologically significant events. In the auditory channel, humans are highly attuned to emotional signals in speech and music that arise from shifts in the frequency spectrum, intensity, and rate of acoustic information. We found that changes in acoustic attributes that evoke emotional responses in speech and music also trigger emotions when perceived in environmental sounds, including sounds arising from human actions, animal calls, machinery, or natural phenomena, such as wind and rain. The findings align with Darwin’s hypothesis that speech and music originated from a common emotional signal system based on the imitation and modification of sounds in the environment.

Abstract

Emotional responses to biologically significant events are essential for human survival. Do human emotions lawfully track changes in the acoustic environment? Here we report that changes in acoustic attributes that are well known to interact with human emotions in speech and music also trigger systematic emotional responses when they occur in environmental sounds, including sounds of human actions, animal calls, machinery, or natural phenomena, such as wind and rain. Three changes in acoustic attributes known to signal emotional states in speech and music were imposed upon 24 environmental sounds. Evaluations of stimuli indicated that human emotions track such changes in environmental sounds just as they do for speech and music. Such changes not only influenced evaluations of the sounds themselves, they also affected the way accompanying facial expressions were interpreted emotionally. The findings illustrate that human emotions are highly attuned to changes in the acoustic environment, and reignite a discussion of Charles Darwin’s hypothesis that speech and music originated from a common emotional signal system based on the imitation and modification of environmental sounds.