Effect of duration on the frequency discrimination of individual partials in a complex tone and on the discrimination of fundamental frequency.

Thresholds for the discrimination of fundamental frequency (F0DLs) and frequency difference limens (FDLs) for individual partials within a complex tone (F0=250 Hz, harmonics 1–7) were measured for stimulus durations of 200, 50, and 16 ms. The FDLs increased with decreasing duration. Although the results differed across subjects, the effect of duration generally decreased as the harmonic number increased from 1 to 4, then increased as the harmonic number increased to 6, and finally decreased for the seventh harmonic. For each duration, F0DLs were smaller than the smallest FDL for any individual harmonic, indicating that information is combined across harmonics in the discrimination of F0. F0DLs predicted from the FDLs corresponded well with observed F0DLs for the 200- and 16-ms durations but were significantly larger than observed F0DLs for the 50-ms duration. A supplementary pitch-matching experiment using two subjects indicated that the contribution of the seventh harmonic to the pitch of the 16-ms complex tone was smaller than would be predicted from the FDL for that harmonic. The results are consistent with the idea that the dominant region shifts upward with decreasing duration, but that the weight assigned to individual harmonics is not always adjusted in an optimal way