What is it about the big, earth-shattering climaxes in Mahler symphonies or the violent finales of Beethoven string quartets that gets audiences’ hearts racing?

A team of researchers at UCLA has found evidence that human listeners can be aroused by the characteristics of music that resembles the cries of animals in distress. "Music that shares aural characteristics with the vocalizations of distressed animals captures human attention and is uniquely arousing," said Daniel Blumstein, chairman of UCLA's department of ecology and evolutionary biology.

Blumstein is an authority on animal distress calls, particularly among marmots. In the natural world, animals in distress cry out with a kind of distortion in their voice, the result of air being forced rapidly through the vocal system. The effect shows up in the yelps of young marmots and other animals when they are separated from their parents.

The findings, which were published online June 12 in the journal Biology Letters, are based on a series of experiments that Blumstein designed and conducted with Peter Kaye, a film and TV composer, and Greg Bryant, an assistant professor of communication at UCLA.

The study was carried out using undergraduate students who were asked to listen to two types of music and then rate the two examples based on how it made them feel. The first clip featured a kind of “generic and emotionally neutral” music played on synthesizers – e.g. elevator music. The second clip introduced sudden shifts in pitch and distortion, similar to guitar distortion in rock music.

When the music featured distortion, subjects rated it as more exciting than the compositions without distortion.

A second part of the study was carried out pairing the same snippets of music with 10-second video clips designed to be boring (showing, for example, someone walking or drinking coffee). The researchers found the addition of the video seemed to eliminate the exciting effect of the distorted music. However, the negative emotions associated with the distortion in the music did not go away.

Since humans rely heavily on their vision, the viewers may have disregarded the alarm signals in the music when they saw the benign scene in the video.

According to UCLA, Blumstein’s study is the first work to incorporate what scientists know about animal communication into the study of music perception.

Of course, not all distortion or dissonance is created equal and it remains to be seen whether the study's findings are applicable across cultures and societies. Nevertheless, it adds to our collective understanding of why certain types of music are more innately appealing than others. Last fall, a group of Italian researchers found that a preference for consonance may be hard-wired into our brains.