Effects of white noise on the most comfortable level for speech with normal listeners.

This study assessed the effects of noise level on the most comfortable level (MCL) for discursive speech. Normal young adults (N:25) were instructed to search thoroughly around their MCL by Bekesy tracking. Mean MCL in quiet was 82.5 db SPL (S.D. = 11.1 db) which was statistically indistinguishable from group MCLs in noises of 55 and 70 db SPL. However, MCL rose to 90.9 and 100.3 db in noises of 85 and 100 db SPL, respectively. These mean MCLs were somewhat higher than observed previously and may be due to differences in instructions and procedures in threshold-tracking.