How to Keep Workers Safe From Loud Music
People who work at weddings, bars and restaurants are often exposed to loud noise. How do you protect these workers from noise hazards?
- By Bernard Fontaine
- Aug 22, 2022
Most people have attended a wedding at a venue where recorded or live music is playing with powerful speakers. Bartenders, restaurant wait staff, photographers, videographers, disc jockeys, band members are exposed to elevated noise while the music plays. Such joy and family love are evident and shared from the moment the guests arrived. But by the end of a long, very loud day and evening despite all the wonderful camaraderie, many people find their ears are “ringing” after leaving the venue. While the tinnitus may be short lived, workers who are repeatedly exposed to noise may lead to permanent hearing loss. Finances Online and SICODE.com reported in 2021 that there are half a million restaurant locations in the United States employing 14.6 million workers. Many fast-food or quick serving restaurants would not be of concern but there are many other party restaurants with entertainment and music bars.
Except for some metropolitan areas like New York City, there is no state or federal legislation or noise restrictions at these venues, that limit indoor noise to the public. When considering all of the affected workers within the Standard Industrial Code 5812, many are overtly exposed to elevated noise levels intermittently for four hours or more. Most employers or caterers fail to consider the noise levels as an occupational health hazard. No hearing protection, training or education, or audiometry is provided to meet the regulatory compliance requirements of the OSHA Hearing Conservation Standard (29 CFR 1901.95). Less noise, but still significant, is evident during a reception when the guests converse among each other without background music. But even without any noise from the entertainment, the noise from many people talking in one room can be relatively loud.
Our team was interested in learning more about how much noise was present at the dinner tables and dance floor about 50 feet from the speakers. Waiters, videographers and photographers mingled with the patrons intermittently while serving food, refilling water and wine glasses, and clearing tables. Their personal exposure to noise varies depending on the time and duration of exposure within the venue as well as their relative location to the noise source. Time spent away from the music varied depending on their assigned work task and requests from the patrons.
Method Used to Evaluate Noise Exposure
To evaluate the noise levels, we used the National Institute for Occupational Safety and Health (NIOSH) Sound Level Meter (SLM) application (app). The application has the same features of professional sound levels meters and noise dosimeters combined into a simple, easy-to-use mobile telephone app. The technology was developed by NIOSH to help people make informed decisions about their noise environment and promote better hearing health and prevention efforts. It was tested and validated (accuracy ± 2 dBA) according to standards in a reverberant chamber at the NIOSH acoustics lab – the only proper method to validate accuracy. NIOSH estimates there are millions of workers exposed to hazardous noise levels every year. In addition to damaging workers’ quality of life, occupational hearing loss carries a high economic price to society.
In this study, we looked at the noise exposure over a period of 37 minutes while the music played and the workers serviced the patrons. The Leq was 97.3 dB, A -weighted exposure (dBA) for a noise dose of 130% for the timeframe. At that noise level, workers could be exposed for only 2.6 hours. The projected 4-hour noise dose would have been about 843%. In essence, if workers were anywhere near the dance floor and dinner tables for that length of time or more, they would be overexposed to noise levels above the federal OSHA maximum Permissible Exposure Limit (PEL) of 95 dBA for the four hours. The Lmax during the timeframe was 110.1 dB. These noise exposures were well above the OSHA Action Limit (AL) of 85 dBA for an 8-hour Time-Weighted Average (TWA) exposure, which requires workers to wear hearing protection, implement a hearing conservation program and train for those workers working more than 30 events a year.
The Heath Safety Executive (HSE) recommends that the A-weighted equivalent continuous sound level over the duration of the event (Leq) in any part of the audience area should not exceed 107 dB, and the C-weighted peak sound pressure level should not exceed 140 dB. These sound-level exposure values are recommended for the entire audience area. For practical purposes, it is usual for audience sound-level exposure to be monitored close to the front of house sound mixing position. For the largest outdoor and indoor venues, this can be up to 75m from the front-of-stage barrier position where the audience sound-level exposure can be significantly higher than at the front-of-house sound mixing position.1
Where practical, the audience should not be allowed within 3m of any loudspeaker. This can be achieved by the use of approved safety barriers and dedicated stewards, wearing appropriate hearing protection. Where this is not practical, the overall music sound levels will have to be modified so that people closer than 3m to the loudspeakers. Under no circumstances should the audience and loudspeaker separation distance be less than 1m. Similarly, sources of noise other than music also need to be properly controlled. In particular, the noise from pyrotechnics should be restricted so that at head height in the audience area, noise from pyrotechnics does not exceed a C-weighted peak sound pressure level of 140 dB.2
Occupational Noise Exposure of Employees at Locally-Owned Restaurants
While many restaurant employees work in loud environments, in both dining and food preparation areas, little is known about worker exposures to noise. The busier the restaurant or bar, the louder the noise levels even without music or other forms of entertainment. The risk of hearing loss to millions of food service workers around the country is unknown. This particular study evaluated full-shift noise exposure to workers at six locally-owned restaurants to examine risk factors associated with noise exposures during the day shift. It is known that evening and late nights traffic can influence the noise levels.
Participants included cooks, counter attendants, bartenders, and waiters at full-service restaurants with bar service and at limited-service restaurants that provided counter service only. Assessments were made on weekdays and weekends, both during the summer and the fall (with a local university in session) to examine whether the time of week or year affects noise exposures to this population in a college town. In addition, the relationships between noise exposures, type of restaurant and the job classification were assessed.
One-hundred eighty full-shift TWA exposures were assessed, using both OSHA and NIOSH criteria. No TWA measurements exceeded the 90 dBA OSHA 8-hour PEL, although six projected TWAs exceeded the 85 dBA OSHA hearing conservation action limit. Using NIOSH criteria, TWAs ranged from 69-90 dBA with a mean of 80 dBA (SD = 4 dBA). Nearly 8 percent (14) of the exposures exceeded the NIOSH 8-hour 85 dBA.
Full-shift exposures were larger for all workers in full-service restaurants (p < 0.001) and for cooks (p = 0.003), regardless of restaurant type. The fall semester (p = 0.003) and weekend (p = 0.048) exposures were louder than summer and weekdays. Multiple linear regression analysis suggested that the combination of restaurant type, job classification, and season had a significant effect on restaurant worker noise exposures (p < 0.001) in this college town. While evening/night shift exposures, where noise exposures may be anticipated to be louder, were not assessed, this study identified that restaurant type, job classification, time of week, and season significantly affected the noise exposures for day-shift workers. Intervention studies to prevent noise-induced hearing loss (NIHL) should consider these variables.
Noise Hazard to Employees in Local Discotheques
There is growing concern that amplified music in discotheques can cause hearing loss. This study attempts to evaluate the noise hazard of employees exposed to amplified music in our discotheques. Employees comprising of disc jockeys, bartenders, waiters, cashiers and security officers of five selected discotheques were used for the study. Personal noise dosimetry was carried out on 40 employees throughout their work shift. The audiometric examination results of another 46 employees were compared with 37 subjects from a non-exposed match control group.
The range of exposure to noise level above 85 dBA for the employees is 3.6 to 6.9 hours with a mean of 5.1 hours. All the occupational groups are exposed to noise level of at least 89 dBA Leq for their whole work shift. The discotheque group has statistically significant higher prevalence (41.9 percent) of early sensorineural hearing loss compared to the control group (13.5 percent). A higher proportion of employees in the older age group (above 30 years old) and working longer (above 1 year) suffer from hearing loss. A significant proportion of the discotheque study subjects (21 percent) also complained of recurrent tinnitus compared to 2.7% in the control group. The younger (< 30 years) and those with shorter exposure duration (< 1 year) appeared to complain of tinnitus more.
In conclusion, the study shows that all the employees regardless of occupations are exposed to noise above the permissible level of 85 dBA Leq. A high proportion of these workers also suffer from early sensorineural hearing loss and tinnitus.
Noise Exposure and Hearing Loss in Student Working in University Entertainment Venues
Most studies to date on sound levels in entertainment establishments have concentrated on exposure levels for the attending public, rather than employees who may be at greater risk of hearing loss. Of particular concern are young employees. The aim of this pilot study was to estimate typical sound levels in different areas where amplified music was played, measure temporary threshold shift (TTS) and estimate the dependence of hearing threshold shifts on measured noise levels.
This study focused on students who were working part-time (up to 16 h/week) in music bars and discotheques in a university entertainment venue. All 28 staff were invited to participate in the study. Pre- and post-exposure audiometry was used to determine hearing threshold at both high and low frequencies. Personal dosemeters and static measurements were made to assess noise levels and frequency characteristics. A questionnaire was used to determine patterns of noise exposure and attitudes to noise levels and hearing loss.
Of the 28 student employees working in the three areas, 14 (50 percent) agreed to take part in the study, giving 21 pre- and post-shift audiograms. The mean personal exposure levels for security staff were higher than those of bar staff, with both groups exceeding 90 dB(A). The maximum peak pressure reading for security staff was 124 dB. Although TTS values were moderate, they were found to be highly significant at both low and high frequencies and for both ears. Twenty-nine per cent of subjects showed permanent hearing loss of more than 30 dB at either low or high frequencies. The correlation between TTS and personal exposure was higher at 4 kHz than the low and high frequencies.
Contemporary music may be an important yet little considered contributor to total personal noise exposure, especially amongst young employees. Employees need to be better informed of risks of hearing loss and the need to report changes in hearing acuity. Suggestions are made on strategies for improving the assessment of noise exposure in entertainment venues.
Conclusion
Restaurants, bars and other venues that provide loud music or other forms of entertainment should evaluate their workers’ noise exposure. Not all venues are the same. Risk assessments for noise provide an understanding of the potential occupational risk. Evaluations should be repeated since noise levels and sources of exposure will vary based on the number of patrons, frequency and duration of exposure, type and location of speakers, and other confounding factors. Hence, the collected data should be statistically sound to determine if workers are repeatedly exposed above federal OSHA standards and what controls should be implemented to protect those workers at-risk from losing their hearing.
Engineering controls should be considered to absorb some of the sound by evaluating the acoustics where the music is played. Some venues can install a noise limiting device (sound limiter) to monitor the noise the room and if it goes over a certain level it will cut off the electrical system within the room. Most sound limiters are set to around 80 to 90dBA. Administrative controls should be considered to reduce the time of exposure. Ask if there are any noise limits or protocols for the DJ or orchestra/band. Inquire about other rooms or spaces where workers can retreat if it gets too loud. Taking a short break periodically can reduce the exposure time. Provide workers with adequate hearing protection (i.e., ear plugs or ear muffs). Audiometric exams should be offered for any worker who may be exposed to elevated noise levels for more than 30 days a year. Finally, hearing conservation training should be provided to inform workers about the effects of noise on their hearing and the outcome of any audiometric testing.
References
- Local Law 113 of the City of New York, 2005 as amending previous Local Law 22 of the Administrative Code of New York City (2002).
- Green DR, Anthony TR. Occupational Noise Exposure of Employees at Locally-Owned Restaurants in a College Town. J Occup Environ Hyg. 2015;12(7):489-99.
- Sadhra S, Jackson CA, Ryder T, Brown MJ. Noise exposure and hearing loss among student employees working in university entertainment venues. Ann Occup Hyg. 2002 Jul;46(5):455-63.