Researchers have now been successful in understanding why certain sounds like fingernails on a chalkboard gets some people on the edge. It is the shape of the human ear that
may amplify certain aspects of such sounds to make it even more annoying to the listener. Also people's perceptions about these irritating sounds might increase the stress levels making it more annoying. The frequency of such screechy sounds ranges between 2,000 to 4,000 Hz. The human ear is the most sensitive during this range.
The study was conducted by musicologists Christoph Reuter, of the University of Vienna and
Michael Oehler, of the Macromedia University for Media and
Communication in Cologne, Germany. The subjects were divided into two groups. One group was told that they would be listening to contemporary music while the other group was aware of the squeaking sound they were about to hear. Measurable physical reaction was seen in both the groups. But the group who thought they were listening to contemporary music judged the
sound as slightly less unpleasant.
The results of the study will be presented at the
annual meeting of the Acoustical Society of America in San Diego.