Characteristics of noise exposure during solitary trumpet playing: immediate impact on distortion-product otoacoustic emissions and long-term implications for hearing.

OBJECTIVES: The objectives of this investigation were to quantify noise exposures generated during a 1 hr trumpet practice session and to determine whether distortion-product otoacoustic emissions (DPOAEs) are affected by such exposure, to describe the distribution of intensity levels and temporal characteristics of noise produced by trumpet practice, and to determine the effect of earplug use on generated noise levels and DPOAEs.
DESIGN: In experiment 1, eight college-age trumpeters underwent an otoscopic inspection, tympanometry, and pure-tone threshold testing. Using a Grason-Stadler 60 DPOAE system, DPOAEs were recorded just before a 1 hr practice session, at 2 min after the practice session, 4 min after the session, and at 4 min intervals thereafter for a total period of 1 hr. A Hewlett-Packard 3569A Real-Time Frequency Analyzer was used to integrate noise levels to assess the overall level of exposure averaged over the course of the hour. In experiment 2, seven different trumpeters participated in two data-collection sessions. The main difference between the sessions was that subjects wore E.A.R. earplugs during session 2. All other design parameters were similar to those of experiment 1.
RESULTS: Noise levels generated during the practice sessions resulted in average Leqs of 95.96, 96.6, and 96.43 dB SPL. A sound-distribution analysis revealed that noise levels exceeded 85 dB for an average of 43.73 min per session. Mean Leq values did not change when subjects wore earplugs (96.6 dB SPL versus 96.43 dB SPL.) Predictions (ISO 1999) of the increased risk of hearing loss that trumpeters would experience at 40, 50, and 60 years of age were made and indicated that trumpeters are at a significantly increased risk of hearing loss over that contributable to age alone. This increased risk is apparent with as little as 1 hr of exposure per day and suggests that 60-year-old male and female musicians exposed to trumpet noise for 4 hr per day for 40 years would be 85% and 300%, respectively, more likely to have hearing loss than their peers with negative noise exposure histories. Statistically significant decreases in DPOAE amplitudes from the prenoise exposure collection point to the 2 min post exposure point were observed only when subjects were not wearing earplugs during their practice session. Recovery of DPOAEs to baseline level varied in form for four test frequencies.
CONCLUSION: During solitary play, trumpeters generate noise levels that temporarily decrease DPOAE amplitudes and that by themselves have the potential to result in permanent noise-induced hearing loss. Trumpeters who practice/perform over a period of years should be concerned about the implications of their craft on their hearing and should be offered personalized hearing conservation programs. The use of earplugs offers a practical and cost-effective means of hearing protection and, for this group of trumpeters, did not lead to an increase in playing level.