Perceived continuity of gliding and steady-state tones through interrupting noise

Perceived continuity was studied by varying the direction (steady-state, upward glide, or downward glide), the frequency separation, and the slope of two sinusoidal tones separated by a louder burst of white noise. When the two tones had different directions, continuity was perceived according to a frequency-proximity principle (frequency-interpolation effect). On the other hand, when the tones had the same direction, continuity was perceived on the basis of a good-continuation principle (frequency-extrapolation, or frequency-trajectory, effect). We attempted to determine the degree of tuning of the frequency-extrapolation mechanism. Our results showed that there was some tuning for the starting frequency of the postnoise glide; in this case, the region of acceptance for continuity was centered around a frequency predicted from the trajectory of the prenoise glide. No evidence was found for tuning based on the slope of the sinusoidal tones. These results suggest that auditory processes need to analyze the postnoise sound before deciding whether the prenoise tone continued underneath the noise burst.