Dissertation
Assessment and control of occupational sound exposures for music instructors
University of Iowa
Doctor of Philosophy (PhD), University of Iowa
Spring 2020
DOI: 10.17077/etd.005290
Abstract
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.
Details
- Title: Subtitle
- Assessment and control of occupational sound exposures for music instructors
- Creators
- Kathryn J Crawford
- Contributors
- T. Renee Anthony (Advisor)Nathan Fethke (Committee Member)Stephanie Fleckenstein (Committee Member)Faryle Nothwehr (Committee Member)Thomas Peters (Committee Member)
- Resource Type
- Dissertation
- Degree Awarded
- Doctor of Philosophy (PhD), University of Iowa
- Degree in
- Occupational and Environmental Health
- Date degree season
- Spring 2020
- Publisher
- University of Iowa
- DOI
- 10.17077/etd.005290
- Number of pages
- xv, 161 pages
- Copyright
- Copyright 2020 Kathryn J Crawford
- Language
- English
- Description illustrations
- illustrations (some color)
- Description bibliographic
- Includes bibliographical references (pages 139-142).
- Public Abstract (ETD)
Music instructors are exposed to loud sound while teaching and performing music that could lead to hearing loss. Earplugs may help reduce exposure, but they might block sounds instructors need to hear. This is likely why most instructors do not wear them. Earplugs can be hard to fit and if not used correctly, they do not block sound well. The goals of this study were to measure sound exposures for music instructors, test three types of earplugs to see how well they worked and if instructors were willing to wear them, and to estimate the effects wearing earplugs may have on reducing the exposures.
Music instructors wore devices to measure the sound they were exposed to during the day for multiple weeks. They filled out an activity log recording daily work activities. These data were used to determine if daily exposures exceeded recommended limits and to identify the loudest activities. Separately, three types of earplugs (foam, and non-custom and custom “musicians’ earplugs”) were tested to see how much they reduced and distorted sound. Study participants completed surveys over six months to explain the pros and cons of each type of earplug. Lastly, all of these data were combined and used to estimate if the earplugs worked well enough to reduce sound exposure if they were worn during the loudest activities. Results indicated music instructors are exposed to high sound levels. Earplugs need to be worn whenever sound levels reach 90 dBA in order to reduce the risk of hearing loss.
- Academic Unit
- Occupational and Environmental Health
- Record Identifier
- 9983949497002771
Metrics
13 File views/ downloads
68 Record Views