The effects of speech presentation level on acceptance of noise in listeners with normal and impaired hearing.

PURPOSE: To compare the effects of speech presentation level on acceptance of noise in listeners with normal and impaired hearing. METHOD: Participants were listeners with normal (n = 24) and impaired (n = 46) hearing who were matched for conventional acceptable noise level (ANL). ANL was then measured at 8 fixed speech presentation levels (40, 45, 50, 55, 60, 65, 70, and 75 dB HL) to determine if global ANL (i.e., ANL averaged across speech presentation levels) or ANL growth (i.e., the slope of the ANL function) varied between groups. RESULTS: The effects of speech presentation level on acceptance of noise were evaluated using global ANLs and ANL growth. Results showed global ANL and ANL growth were not significantly different for listeners with normal and impaired hearing, and neither ANL measure was related to pure-tone average for listeners with impaired hearing. Additionally, conventional ANLs were significantly correlated with both global ANLs and ANL growth for all listeners. CONCLUSION: These results indicate that the effects of speech presentation level on acceptance of noise are not related to hearing sensitivity. These results further indicate that a listener's conventional ANL was related to his or her global ANL and ANL growth.