Effects of Dark-Bright Timbral Variation on the Perception of Flatness and Sharpness

Fifty undergraduate music majors listened to 48 pairs of clarinet tones. Both tones in each pair were three seconds long, the interstimulus interval lasted one second, and the interval between trials was ten seconds. The subjects' task was to indicate whether the pitch of the second tone sounded sharp, flat, or the same as the first pitch. The tones had been altered by an audio equalizer so that they were either bright or dark relative to the original recorded level. The equalized tone pairs thus consisted of bright-bright, dark-dark, bright-dark, and dark-bright sequences. In addition, the second tone was adjusted to either 12 cents sharp, 12 cents flat, or was left unaltered. Analyses of response error patterns suggest that subjects associated darkness with flatness and brightness with sharpness.