Assessment and control of occupational sound exposures for music instructors

Music instructors’ daily job requirements generate high sound levels that could potentially lead to overexposure. Adverse outcomes associated with high exposure to sound, such as hearing loss and tinnitus, can be especially devastating to music instructors as hearing is essential to both job performance and career reward. There are numerous options available for hearing protection devices (HPD) which may offer protection to music instructors; however, studies have reported that musicians, especially students and instructors, do not wear them and those that do, may not achieve adequate fit or sound reduction with them. The goals of this study were to characterize sound exposures for music instructors, evaluate the effectiveness of three types of HPD, and to use Monte Carlo methods to generate risk profiles to simulate the effects of different control strategies on estimated exposures for music instructors. Personal sound exposure measurements from music instructors were collected during full workdays for up to four weeks in an academic year using dosimeters. Study participants completed an activity log recording work-related activities throughout the day. Dosimeters logged both one-second and one-minute sound equivalent levels in A-weighted decibels (dBA). These data were used to calculate eight-hour time-weighted averages, daily dose, and task-specific contributions to that dose determine if daily exposures exceeded recommended limits and to identify high-exposure tasks that could be targeted for future intervention. Separately, audiometric testing was performed to determine the attenuation newly trained users achieved with three types of HPD (formable foam earplugs, and non-custom and custom versions of uniform attenuation earplugs). Attenuation levels were compared to manufacturer ratings and used to calculate a coefficient of variation to determine how much HPD were reducing and distorting sound. Surveys completed by participants over a six-month follow-up period provided information regarding the benefits and barriers musicians perceived while wearing each HPD. Lastly, exposure, attenuation, and frequency of HPD use data were combined and used as inputs in Monte Carlo simulations to estimate musicians’ long-term exposure to sound and the effects of control strategies (e.g., wearing HPD) may have on reducing exposure. Results from these studies indicate a substantial portion of daily and weekly exposures of music instructors exceed recommended limits and thus are at risk of hearing loss. The sampled groups with the highest risk are brass and conducting instructors. Activities that contributed the most to daily dose included group rehearsals, personal practice sessions, and performances. Participants achieved substantial variability in attenuation for all three types of HPD. The custom and non-custom uniform attenuation earplugs were the most appropriate options for musicians, but participants reported barriers to wearing these HPD including comfort, cost, and difficulty in inserting them. Estimates from Monte Carlo simulations indicated that either type of HPD could effectively reduce musicians’ exposure but only if they are worn for 95% of lessons, rehearsals, practice sessions, and performances. Alternatively, the most effective strategy identified in simulations for reducing exposure was wearing HPD any time an activity reached 90 dBA. Future studies should explore ways to provide real-time feedback to music instructors informing them of these high-exposure scenarios so they know when wearing HPD would be most effective.