How the art of noise makes itself heard

A study has found that vertebrates in distress emit non-linear sounds that are harsh and unpredictable and humans evoke these patterns in movie soundtracks to excite viewers' emotions.

Women scream in horror movies ("Aaaaaahhhh!"). Men scream in adventure movies ("Yippee-ki-yay!"). The sound goes from quiet to screamingly loud and back again in war movies (silence, bomb, silence, bomb). And dramas have not so much screaming. That, in brief, is the summary of a new study in the journal Biology Letters by a three-man team led by an evolutionary biologist at the University of California at Los Angeles.

Dan Blumstein, the biologist, and author of such works as "The structure, meaning, and function of yellow-bellied marmot pup screams", had observed that vertebrates in distress emit non-linear sounds that are harsh and unpredictable. He wondered whether humans evoke these patterns in movie soundtracks to excite viewers' emotions. He and his colleagues, Richard Davidian of UCLA and Peter Kaye of the music school at England's Kingston University, devised a test.

They extracted 30-second musical highlights from 102 great movies, as assessed by internet polling. They then dissected the elements of those snippets and compiled them for their four classes of movies: horror, adventure, drama and war. The numbers confirmed that, yes, movies use non-linear sound to manipulate the audience, be it "the overblowing of the brass and wind instruments, the metallic rasp of the stopping of the French horns, or directing the string players' bow strength and location". The tricks lie not only in the playing but the composition: "the use of harmonic dissonance, trills, vibrato and sudden pitch change and ... tremolo string bowing, flutter-tonguing wind instruments."

Prof Blumstein wrote in an e-mail to this newspaper that "the first scream in Psycho is great and illustrated everything. The music is noisy and chaotic. The scream is noisy. It's chilling." His team further noted that inhuman sounds can also prove handy for sound mixers. The 1933 King Kong was the first movie to use and manipulate animal sounds, and "this is still the practice for many prehistoric, alien or otherwise monstrous cinematic characters".

In a more recent example, the roar of the aviator Chewbacca in the Star Wars movies combines walrus, badger, bear and camel noises. In the same vein, the actor Sir Laurence Olivier once said that when he wished to produce a blood-curdling scream as King Oedipus, he thought of ermines that the Inuit trap by putting salt on the ice; when the ermines lick the salt, their tongues freeze to the surface and they are doomed.

But what does the Blumstein study prove? It proves, he said in his e-mail, "that we're mammals and have a response similar to other mammals - particularly in how we respond to familiar sounds". * The National