To assess the risk of noise-induced hearing loss among musicians in the Chicago Symphony Orchestra, personal dosimeters set to the 3-dB exchange rate were used to obtain 68 noise exposure measurements during rehearsals and concerts. The musicians' Leq values ranged from 79-99 dB A-weighted sound pressure level [dB(A) 1. with a mean of 89.9 dB(A). Based on 15 h of on-the-job exposure per week, the corresponding 8-h daily L~ (excluding off-the-job practice and playing) ranged from 75-95 dB(A) with a mean of 85.5 dB ( A) . Mean hearing threshold levels (HTLs) for 59 musicians were better than those for an unscreened nonindustrial noise-exposed population (NINEP), and only slightly worse than the 0.50 fractile data for the ISO 7029 ( 1984) screened presbycusis population. However, 52.5% of individual musicians showed notched audiograms consistent with noise-induced hearing damage. Violinists and violists showed significantly poorer thresholds at 3-6 kHz in the left ear than in the right ear, consistent with the left ear's greater exposure from their instruments. After HTLs were corrected for age and sex, HTLs were found to be significantly better for both ears of musicians playing bass, cello, harp, or piano and for the right ears of violinists and violists than for their left ears or for both ears of other musicians. For 32 musicians for whom both HTLs and Leq were obtained, HTLs at 3-6 kHz were found to be correlated with the Leq measured.

Hearing threshold and survey data collected over 3 years in a university school of music indicate that 52% of undergraduate music students show declines in high-frequency hearing at 6000 Hz consistent with acoustic overexposure. Declines at 4000 Hz have grown in number over the 3 years, from 2% the first year to 30% in the third year. These “noise notches” are seen in all instrument groups, including voice, and are seen more in the right ear than the left ear in all groups. Exposure to outside noise does not appear to be a determining factor in who develops these declines. It is concluded that genetic predisposition is a likely risk factor.