Musical pitch

Pitch-matching tests were conducted with learning disabled (LD) and non-learning disabled (NLD) third through fifth graders to examine whether a significant difference between pitch-matching abilities exists. Subjects were given a two part pitch-matching test using a tape recorded vocal model. The vocal model was a 12 year-old boy with unchanged voice singing the test examples on the neutral syllable "loo." Subjects were instructed to echo the vocal model and were given a single point for each correctly sung pitch. Statistical analysis revealed a significant difference in the pitch-matching skills of the learning disabled and the non-learning disabled students.

The convention of representing pitch distances within a circular symmetric scheme has a long history. Perception of the pitch pattern of pairs of circular tones (Shepard, 1964) was examined in three different orderings of the comparison tone. Consistent with previous reports, when tone pairs were randomized the pitch was equally likely to be judged as ascending or descending as the frequency change neared the half-octave. In the ordered conditions, the pitch boundary was sensitive to the direction of frequency change such that hysteresis effects were observed for all subjects. A matrix was constructed of directional pitch judgments to all pairs of circular tones presented randomly. Perception of selected pairs was then predicted on the basis of map region consistency. The results indicate that perception of pitch change is influenced not only by the frequency difference between members of a pair, but also by preceding percepts.