Effects of reverberation on acceptable noise level measurements in younger and older adults.

Acceptable noise level (ANL) test materials were digitally modified to create five reverberant conditions by applying different values of reverberation time (RT) to a non-reverberant condition (RT = 0, 0.4, 0.7, 1.2, and 2 s). Two groups of 12 subjects participated: younger individuals (22–29 years, M = 24.3) and older adults (50–69 years, M = 57.5). Mean hearing threshold levels (250 to 8000 Hz) for both groups were 30 dB HL or better. Most comfortable listening level (MCL) and background noise level (BNL) measurements were completed in each reverberant condition, and from these measurements, ANLs were calculated. Significant main effects for age and reverberation were not found for ANL or MCL. These results suggest that reverberation does not affect the amount of background noise individuals are willing to accept, or the level of speech individuals choose as the MCL. These results can be used by clinical audiologists to counsel patients regarding the use of communication strategies. Additionally, these results can be used to support previous findings that ANL is not related to the intelligibility of the speech signal.