Author(s)
Ravi R. Shah, MD
Jonathan J. Suen, AuD
Ilana P. Cellum, AuD
Jaclyn B. Spitzer, PhD
Anil K. Lalwani, MD
Affiliation(s)
University of Pennsylvania
Abstract:
Educational Objective: At the conclusion of this presentation, the participants should be able to explain the short term effects of subway noise on hearing, discuss the potential long term consequences of chronic exposure to subway noise, and compare possible mechanisms for the observed effects of subway noise on hearing. Objectives: To determine how subway noise exposure affects commuters' hearing. Study Design: Randomized crossover trial. Methods: Twenty subjects were exposed to subway platform noise for 15 minutes, either with or without hearing protection. Pre- and post-exposure pure tone audiometry (PTA) and otoacoustic emissions (OAEs) were compared to assess for temporary threshold shift. After a one week washout period with no subway use, subjects switched hearing protection groups and repeated the process for a second exposure. Results: A statistically significant improvement in PTA thresholds after subway noise exposure was identified, for subjects with and without hearing protection (p<0.001). For exposure without hearing protection, the mean threshold was 5.19 dB pre-exposure and 3.91 dB post-exposure (decrease of 1.28 dB; 95% CI, 0.82 1.74). For exposure with hearing protection, the mean threshold was 4.81 dB pre-exposure and 3.47 dB post-exposure (decrease of 1.34 dB; 95% CI, 0.89 1.79). Thresholds returned to baseline during the washout period. Conclusions: Interestingly, subjects exposed to subway noise exhibited a temporary increase in hearing acuity. A longitudinal study of subway commuters could provide a clearer picture of long term effects on hearing. Still, due to the potential for hidden hearing loss and other adverse effects associated with excessive noise, designing future stations to mitigate commuter noise exposure remains an important public health goal.