Abstract
Patients with unilateral perceptive hearing loss have been examined to determine whether masking of the good ear influences the difference limen of intensity. The measurements were carried out with the aid of the SISI procedure using increments of different magnitudes, until the psychometric function was determined both without and with masking (80 dB SPL). The level of the test tone was maintained constant (20 dB above the threshold determined without masking). At 1000 and 4000 cps, the contralateral noise resulted in a significant improvement in the intensity discrimination, while no change occurred at 250 cps. With a few exceptions, the masking had no significance for the result of the topognostic SISI test using 1 dB increments.