Distorted music is like animals' distress call

The effect of listening to music with distortion is similar to hearing the cries of animals in distress, say researchers. "Music that shares aural characteristics with the vocalisations of distressed animals captures human attention and is uniquely arousing," said study co-author Daniel Blumstein, the journal Biology Letters reports. In distress, animals distort their voices by forcing a large amount of air rapidly through the voice box. Blumstein, professor of ecology and evolutionary biology at the University of California Los Angeles, US, is an authority on animal distress calls, particularly among marmots. In 2010, he and a team of researchers captured media attention with a study of the soundtracks of 102 classic movies in four genres: adventure, drama, horror and war, according to a California statement. They determined that the soundtracks for each genre possessed characteristic emotion-manipulating techniques. Scores for dramatic films, for example, had more abrupt shifts in frequency, both up and down. Horror films, on the other hand, had more screaming females and distorted sounds. The researchers were even able to detect recordings of animal screams in some scores. The latest findings are based on a series of experiments that Blumstein designed and conducted with Peter Kaye, a Santa Monica-based composer of movie and TV scores, and Greg Bryant, an assistant professor of communication studies at California who specialises in research on vocal communication and evolutionary psychology. Bryant is a musician and recording engineer. Using synthesisers, Kaye and Bryant composed a series of original music pieces of several types or "conditions," with each piece lasting just 10 seconds. "We wanted to see if we could enhance or suppress the listener's feelings based on what's going on with the music," Blumstein said. In the control condition, the music was generic and emotionally neutral, without noise or abrupt transitions in frequency or pitch. Bryant likened it to rather plain elevator music. Another condition began in an easy-listening manner but then suddenly broke into distortion, much like Hendrix famously did at Woodstock. Undergraduate students were asked to listen to an example of each condition and then rate the examples based on two factors: how arousing they found the music and whether the emotional feeling in the music was positive (such as happy) or negative (such as fear-inducing or sad). No subject heard more than one example from any condition. When the music featured distortion, subjects rated it as more exciting than the compositions without distortion. They also were more likely to describe the music as charged with negative emotion. "This study helps explain why the distortion of rock 'n' roll gets people excited: It brings out the animal in us," said Bryant. The researchers also believe their study is the first work to incorporate what scientists know about animal communication into the study of music perception. In the future, the researchers plan to test how different types of music affect a listener's nervous system. Past research has shown that calls of distress raise heart rates and skin conductance among animals.