Comparing F0 discrimination in sequential and simultaneous conditions.

In an influential study, Carlyon and Shackleton [J. Acoust. Soc. Am. 95, 3541-3554 (1994)] measured listeners' performance (d') in fundamental-frequency (F0) discrimination between harmonic complex tones (HCTs) presented simultaneously in different spectral regions and compared their performance with that found in a sequential-comparison task. In this Letter, it is suggested that Carlyon and Shackleton's analysis of the simultaneous-comparison data did not adequately reflect their assumption that listeners were effectively comparing F0's across regions. A reanalysis consistent with this assumption is described. The new results suggest that under the assumption that listeners were effectively comparing F0 across regions, their performance in this task was substantially higher than originally estimated by Carlyon and Shackleton, and in some conditions much higher than expected from the performances measured in a traditional F0-discrimination task with sequential HCTs. Possible explanations for this outcome, as well as alternative interpretations, are proposed.