How come a soundtrack does make a chilling scene?
Recent studies by U.S. scientists have demonstrated that nonlinear sounds, corresponding to a certain sound level, undergo an enrichment of the treble components of the audio spectrum. This is due to an energy transfer of the first harmonics to the higher harmonics, which become squeaky and bouncy, a sign that they go beyond the normal linear range of the instrument or vocal cords.
Distorted noises, sudden fluctuations in frequency, bi-phonation and sounds rich in harmonics, are particularly alarming and emotionally evocative for mammals including apparently, for humans.
These scientists studied four types of films: adventure, horror, drama and war, but they have only found in horror movies and dramas a widespread use of nonlinear sound to amplify the emotional content of an emblematic scene.
The scientists conclude that film editors know very well how to use and manipulate non-linear sounds, for sound effects and ambient background noise, and also to use frequency changes to provoke emotional reactions.
Photo by William Creamer © Shamley Productions, Paramount - 1960