Relations between auditory functions in normal hearing.

The relations among a number of auditory functions were studied by concentration on small interindividual differences in these functions. For this purpose a battery of 12 tests was applied to 50 normal-hearing subjects. The tests included absolute threshold, auditory bandwidth measured with comb-filtered noise in direct and in forward masking, psychophysical tuning curve both in direct and in forward masking, temporal integration measured with intensity-modulated noise, forward- and backward-masking curves, cubic-difference-tone strength, and lateral suppression. In all cases the test frequency was 1000 Hz. Among the relations found, are (1) a positive correlation between the shift of the steep edge of the tuning curve, away from the probe frequency, and the width of the auditory filter as measured with comb-filtered noise, (2) an inverse relation between the width of the tuning curve and the width of the temporal window, and (3) a positive correlation between the width of the auditory filter and the strength of the cubic difference tone. Low correlations among tests were not caused by poor test reliability.