Noise exposure levels in stock car auto racing.

Noise-induced hearing loss associated with the workplace has been well described. Far less is known, however, about the risks to hearing from recreational sources of noise. We investigated the popular sport of stock car racing as a potentially significant source of noise exposure, and we conducted a sound-level survey at a National Association for Stock Car Auto Racing (NASCAR) event. Noise levels measured during the race ranged from 96.5 to 104 dB(A) at 46 meters ( approximately 150 feet) from the track and 99 to 109 dB(A) at 6 meters ( approximately 20 feet) from the track. The peak sound pressure level at 6 meters was 109 dB(A). Although significantly less than that associated with an immediate permanent threshold shift, such an exposure could cause a temporary threshold shift. Alhough hearing protection is recommended, particularly for track employees with longer periods of exposure, racing fans with only occasional exposure to such noise levels are unlikely to develop a permanent noise-induced hearing loss.