Influence of pulsed masking on the threshold for spondees.

The changes in masking for spondee words that result from varying both the level and the interruption rate of a white‐noise masker were studied with 14 normal hearing subjects and 14 subjects with sensorineural hearing loss diagnosed as resulting from cochlear otosclerosis. The masker was a white noise and was presented monaurally at either 90 dB sound‐pressure level (SPL) or 30 dB sensation level (SL). It was either continuous or was pulsed at rates of 1, 10, or 100/sec with 50% duty cycle. During the burst‐off half of each cycle, the noise was either dropped 14 dB in level or was fully interrupted. The masked speech reception threshold (SRT) was not improved re the masked SRT in continuous noise when the 30 dB SL masker was pulsed 100 times/sec. Reduction in masking was observed under all other circumstances of cycling the noise. This reduction was more pronounced when the noise was completely interrupted rather than only modulated by 14 dB, when the masker was at its higher level (90 dB SPL as opposed ...