Estimation of Frequency Resolving Power of Human Hearing by Different Methods: Roles of Sensory and Cognitive Factors

Resumo

Frequency resolving power (FRP) was measured in normal listeners. FRP was estimated on the basis of the maximum resolvable ripple density in rippled-spectrum signals. Two measurement procedures were compared: detection of ripple-pattern change and comparison of rippled-spectrum signals. In the change detection method, two successive sound signals were presented to the listener: a test signal and a reference signal. The test signal contained ripple phase reversals every 400 ms; in the reference signal, the ripple phase was constant. The listener’s task was to identify the test signal. In the comparison method, three signals were presented to the listener. The ripple phase in one of the three signals was opposite to that in other two signals. The listener’s task was to identify the signal different from the other two signals. The signal frequency bands varied from 0.5 to 5 oct at a level of 0.5 of the maximum. At all frequency bands, the change-detection method yielded, on average, 1.75 oct^–1 higher FRP estimates compared to the comparison method. This difference between the two methods is supposed to be due to the greater involvement of cognitive processes (short-term memory) in the comparison method. The change-detection method is more preferable for measuring the sensory component of FRP.