Comparing F discrimination in sequential and simultaneous conditions

In an influential study, Carlyon and Shackleton [J. Acoust. Soc. Am. 95, 3541–3554 (1994)] measured listeners’ performance $\left(d^{\prime }\right)$ in fundamental-frequency $\left(F0\right)$ 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.