Scientists have discovered an evolutionary reason why people find rock 'n' roll exciting: it "brings out the animal in us".

Researchers at the University of California say that the distorted, unpredictable and jarring notes of rock are evocatively primal because the pitch and frequency that make up the music are closely related to the composition make up of the distress calls in animals.

Researchers said that when animals are in distress, they cry out by rapidly forcing a large amount of air through their voice box, which produces a discordant effect intended to grab the attention and trigger an emotional response in other animals.

The latest findings, published in the journal Biology Letters, explain why hearing similar sound patters like Jimi Hendrix's rendition of 'The Star-Spangled Banner' at Wood stock in 1969 instinctually moved so many people and why the music in the shower scene in Alfred Hitchcock's Psycho still sends involuntary chills down our spines.

"Music that shares aural characteristics with the vocalizations of distressed animals captures human attention and is uniquely arousing," researcher Daniel Blumstein, chair of the UCLA Department of Ecology and Evolutionary Biology, said in a statement.

Blumstein is an expert on animal distress calls, particularly when it comes to marmots.

Two years ago, Blumstein and a team of researchers published a study of the soundtracks of 102 classic movies in four genres: adventure, drama, horror and war, and found that the soundtracks for each particular genre had characteristic emotion-manipulating techniques.

For instance scores for dramatic films tended to have more abrupt shifts in frequency, both up and down, while horror films comprised of more screaming females and distorted sounds, and in some cases even animal screams.

In the latest study, based on findings from Blumstein's previous analysis of movie soundtracks, researchers composed a series of original musical pieces of several types or "conditions" that lasted 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.

Researchers described the control 'condition' or music to be like elevator music, generic and emotionally neutral and did not have noise or abrupt transitions in frequency or pitch.

Another 'condition' started in an easy-listening manner but abruptly broke into distortion, much like Hendrix famously did at Woodstock.

Participants in the study were then asked to listen to an example of each condition and then rate the 10-second pieces based on two factors, including how arousing they found the music and whether the emotional feeling in the music was positive or negative.

When the music featured distortion, participants rated the "condition" as more arousing and more negatively charged than the compositions without the distortion.

Scientists believe that the effect of listening to music with distortion is like listening to cries of animals in distress.

"This study helps explain why the distortion of rock 'n' roll gets people excited: It brings out the animal in us," researcher Greg Bryant, an assistant professor of communication studies at UCLA who specializes in research on vocal communication and evolutionary psychology, said in a statement.

The team believes that their study is the first to incorporate knowledge about animal communication into the study of music perception.

"Composers have intuitive knowledge of what sounds scary without knowing why," Bryant said. "What they usually don't realize is that they're exploiting our evolved predispositions to get excited and have negative emotions when hearing certain sounds."

However, researcher found in a second study that when the same musical compositions were paired with 10-second video clips that were designed to be minimally evocative, showing, for example, people walking or drinking a sip of coffee, most of the arousing effects of the jarring composition disappeared.

"The video eliminated how exciting the distorted-sounding music seemed, but it didn't trump the emotional content of the music," Bryant said.

Next, researchers plan on researching the effect of different music compositions on a person's nervous system. Past studies found that calls of distress raise heart rates and skin conductance in animals.