Most people take for granted that the sound of nails on a chalkboard is unpleasant, but most have probably never wondered why. That was not the case for Michael Oehler of the Macromedia University for Media and Communication and University of Vienna's Christoph Reuter, whose new research into the unpleasant sound may have found the root of our dislike. In their research, the two musicologists looked at both physical and psychological reactions to unpleasant sounds. In their experiments, they played the much-maligned sound of nails on a chalkboard to participants as well as other hated sounds such as squeaky styrofoam, forks scrapping against dinner plates, and chalk against slate. Sometimes they told respondents the true source of the sound and in others told them that the sounds were from a musical composition. On the physical end of the experiment, the researchers monitored various vital signs of the participants while the tones were played. The results were fairly dramatic.

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