People are Tuned to Listen for Emotions

Music seems to carry emotional information within its structure: according to research, acoustic features of music universally evoke the same emotions, for example, upward moving melodies and increasing pitch are typically related to happiness instead of sadness. Recently, a study found that in addition to music, environmental sounds also carry emotional information that can be perceived by humans, and that influences perception. Astonishingly, the same sound features that evoke emotions in music also stir up emotions if they are present in everyday, environmental sounds such as the sound of the wind and the calls of animals.

Changes in the environmental sounds resulted in changes in perceived emotions

In the above study, subjects listened to four types of environmental sounds. The sounds were machine sounds like a car engine, animal sounds like a call of a bird or the buzz of a mosquito, and sounds produced by human actions such as breathing and chewing, as well as sounds from nature, like rain and wind. The sounds were manipulated in frequency, intensity and rate, and subjects were asked to rate the sounds in terms of valence (positive-negative) and arousal (calm-energetic). According to the results, changes in the environmental sounds resulted in changes in perceived emotions. In general, louder, faster and higher-frequency sounds were evaluated as more positive as well as more arousing, just as it typically is with musical sounds.
In another task reported in the study, subjects were presented with an image of a face expressing an emotion, then an environmental sound that changed in intensity, rate, or frequency, and finally another image of a face expressing an emotion. The subjects were asked to rate how the emotion expressed by the first face changed, for example did the second face seem happier or sadder than the first face. When the sound presented in between the two images changed in a way that did not correspond to how the facial expression changed (for example, the sound went down in frequency, but the expression became happier) the reaction times of participants were longer. This means that changes in seemingly irrelevant environmental sounds interfered with the task of recognizing changes in emotions expressed by facial expression.

Changes in seemingly irrelevant environmental sounds interfered with the task of recognizing changes in emotions

Emotional cues are highly relevant information for humans. The results of the study show that we continuously monitor all kinds of sounds in our environment and detect emotional cues from them. This brings up several interesting questions: how do the background sounds and music we are exposed to in our daily lives, like the radio or the music playing in a departmental store, affect our everyday emotions and responses? Gloomy weather can make us unhappy - is it partly because of the sounds related to the weather?

The researchers link the results of their study to a hypothesis on the origins of language and music first put forward by Darwin. According to the theory, speech and music both evolved primarily to express emotion, and that this expression of emotion mimics sounds from our natural environment. This means that the commonalities we see in how acoustic features in music, speech an environmental sounds express emotions may stem from the fact that speech and music originally evolved to mimic environmental sounds. Although theories of evolution are of course ultimately impossible to prove or disprove, the commonalities between environmental sounds, speech, and music are intriguing and offer a unique perspective into emotional human existence.

written by ketki karanam



Ma, W., & Thompson, W. F. (2015). Human emotions track changes in the acoustic environment. Proc Natl Acad Sci USA, 112(47), 14563–14568. doi:10.1073/pnas.1515087112