Binaural masking-level difference as a function of masker and test-signal duration

The binaural masking-level difference (BMLD) is measured as a function of duration of the masker (uniform masking noise) and of the test tone (400 and 800 Hz). Four observers used a Békésy tracking method which proved to be a time-saving procedure for BMLD measurements. Although the masked threshold depends on the test-tone duration, the BMLD does not. The latter, however, increases from about 5 to 10 dB as the masker duration increases from 10 to 200 ms.