Noise Exposure and Background Noise Tolerance in Listeners With Normal Audiograms

Abstract

Purpose Tolerance for background noise when listening to speech has been found to vary greatly between individuals, despite clinically similar audiograms. Recent work suggests that listeners at risk for noise-induced hearing loss (NIHL) self-report greater annoyance of background sounds compared with listeners at lower risk for NIHL. To date, the relationship between noise exposure levels and background noise tolerance has not been studied using objective noise exposure level measurements and quantitative (i.e., not questionnaire-based) background noise tolerance measures. Method Acceptable Noise Level (ANL; Nabelek, Tucker, & Letowski, 1991 ) scores and week-long noise dosimetry measurements were obtained for 56 normal-hearing college students, 22 of whom were routinely exposed to levels of noise that exceed recommended exposure limits (higher risk). The remaining 34 participants did not exceed recommended exposure limits (lower risk). Results The lower risk group's average daily noise dose was 26%, whereas the higher risk group accrued an average daily noise dose of 461%. The lower risk group was found to be more tolerant of background noise than the higher risk group, with mean ANL scores of 3.1 dB and 5.4 dB signal-to-noise ratio, respectively. A small but statistically significant relationship between ANL and noise dose was found, indicating that higher levels of noise exposure were associated with lower background noise tolerance. Conclusions Results suggest that young adults at higher risk for NIHL based on objective noise exposure data have a slightly lower tolerance for background noise when listening to speech. These findings open avenues for future work on background noise tolerance in more diverse noise-exposed populations.