A quiet look at the noisiest industry in town.
Patrons of loud concerts and bars are there out of choice and exposed to the noise only occasionally but these venues are places of employment for millions of people across Europe who work in the music and entertainment industry, and for whom the question of choice is less clear.
In the UK, everyone except these workers has been under the protection of revised workplace noise regulations since 2006, but the only industry that deliberately generates the noise which threatens its workers’ hearing was given two more years to prepare.
This was the second major legislative change affecting the music and entertainment business in a year. Last June a smoking ban came into effect in any public building in the UK including bars and music venues, and many pubs organised a ‘farewell to smoking’ evening to mark the cigarette’s last gasp. No such fanfare was given for the noise at work legislation, and the new rules crept quietly into force to regulate the activities of international rock legends and local pub landlords alike.
When the smokers and their ashtrays moved outside compliance with the smoking ban was complete. Keeping within the Noise at Work Regulations involves measuring levels of exposure of staff who may be carrying out many different tasks in many different areas of the premises; it takes much more than the whiff of tobacco smoke to indicate a problem with compliance.
Employees as well as residents now considered
Some businesses are used to managing the noise of their activities, and when Bruce Springsteen opened in May for two nights at the new Emirates Stadium the sound levels at noise sensitive areas outside the venue were not allowed to exceed 75dB and the final encore had to have risen into the London night no later than 10.30pm. Concert organisers are good at meeting licence approval conditions set by local councils to reduce the noise nuisance of their activities, but now they must consider employees as well as local residents.
The nightly 50,000 strong audience paid up to £150 a ticket each to experience Springsteen at 100dB, while stadium staff, contractors and even the musicians themselves were under the protection of legislation designed to protect workers’ hearing – including those in the music and entertainment business. For every well-publicised case of a celebrity musician with damaged hearing there are tens of thousands of workers in the industry receiving equal or greater doses of noise. The 100,000 Springsteen fans may have happily left Islington with ringing ears, but their occasional enjoyment of loud concerts can no longer be at the cost of someone’s hearing, not even that of the Boss himself.
Ringing the changes . . .
Noise at work in any industry can cause hearing loss that may be temporary or permanent, and people often experience temporary deafness or a ringing in their ears after leaving a noisy place such as a concert or disco. Although hearing usually recovers within a few hours, this is a sign that continued exposure to noise at this level may result in permanently damage.
Damage can also be caused immediately by sudden, extremely loud, explosive noises, as from guns or pyrotechnics. But hearing loss is usually gradual, caused by prolonged exposure, and it may only be when damage caused over the years combines with hearing loss due to ageing that people realise how deaf they have become. They will first notice that family or neighbours complain about the television being too loud, or that they can no longer keep up with conversations in a group and have trouble using the telephone.
Eventually everything becomes muffled and they find it difficult to catch sounds like ‘t’, ‘d’ and ‘s’, so they confuse similar words. Hearing loss is not the only problem and many people develop a ringing, whistling, buzzing or humming in the ears called tinnitus, which is a distressing condition that can lead to disturbed sleep and depression.
In the entertainment business it is common for noise levels to reach 110dB(A), the loudness of a chainsaw. The Royal National Institute for Deaf People (RNID) carried out a covert survey in April 2004 of 15 nightclubs in London, Manchester, Cardiff, Edinburgh and Belfast and found that even in chill out areas where they were provided, the noise levels averaged 92.3dB(A), 12 decibels higher than the 80dB(A) recommended for the workplace. At rock concert levels it is possible for staff to receive their legal daily dose of noise in a matter of seconds if mitigating measures are not taken.
The damage is done
Paul Grey spent over 20 years as a rock guitarist touring and recording internationally with bands like Eddie & the Hot Rods, The Damned and UFO. Eighteen of them were tinnitus free but when he realised that his ears were still ringing 2 weeks after a tour had finished, he was found to have significant hearing loss, tinnitus and the onset of hyperacusis, a condition characterised by over-sensitivity to certain frequency ranges of sound and intolerance to normal environmental sounds.
‘Against their advice I continued touring, during which time the tinnitus levels rapidly reached such high levels in both ears that I was unable to sleep or concentrate. Additionally hyperacusis rapidly precluded me from going to pubs, restaurants and even performing onstage became stressful,’ he said. ‘The implications of permanent noise damage go far beyond the working environment – 24 hours a day ringing in both ears, hearing loss, sensitivity to normal noises.’
The dilemma was how can the leisure and entertainment business, from bars and clubs to the big rock concert venues, keep the noise exposure of staff and musicians to within new legal limits without cranking down the enjoyment of patrons? Finding a solution was the task of a music and entertainment sector working group which collaborating with the HSE to create guidance for employers affected by the legislation. The group comprised a wide range of music and entertainment interests such as the Concerts Promoters Association and the Musicians Union as well as representation from the Chartered Institute of Environmental Health.
Its guidance is practical advice on developing noise control strategies which prevent or minimise the risk of hearing damage and helps workers and employers meet legal obligations; following the recommendations will normally be enough to stay within the law, and health and safety inspectors seeking compliance may refer to the guidance as illustrating good practice.
The new regulations and their action levels
The regulations were derived from a European Directive (2003/10/EC), and replace the Noise at Work Regulations 1989 to establish new Exposure Limit Values and Exposure Action Values. Noise is measured in decibels (dB),and an ‘A-weighting,’ sometimes written as ‘dB(A)’, is used to measure average noise levels; a ‘C-weighting’ or ‘dB(C)’ is used to measure peak, impact or explosive noises. Although a person might barely notice a 3 dB increase in noise level because of the way our ears work, a 3 dB change doubles the sound energy and so what might seem like small differences in numbers can be significant. Two instruments of the same 85dB loudness when played together will produce 88dB, and a sound reduction of 3dB halves the sound pressure, and its propensity to damage hearing.
The new regulations set action levels at the following:
- The Lower Exposure Action Value (LEAV) is set at an 8-hour average noise exposure level (or daily personal noise exposure level, LAEP,d) of 80 dB(A) and a peak sound pressure level of 135 dB(C). At this level the employer has to provide information and training and make hearing protection available.
- The Upper Exposure Action Value (UEAV) is set at a LAEP,d of 85 dB(A) and a peak sound pressure level of 140 dB(C), and above this the employer is required to take reasonable, practicable measures to reduce noise exposure, such as engineering controls or other technical measures. The use of hearing protection is mandatory if the noise cannot be controlled by these measures, or in the interim while measures are being planned or carried out.
- There are also exposure limit values of 87dB(A) LAEP,d (daily or weekly exposure) and a peak sound pressure level of 140 dB(C) which must not be exceeded. These exposure limit values take account of any reduction in exposure provided by hearing protection and any club or bar that exceeds this value will be in breach of the law and could face enforcement action.
If noise exposure levels are likely to be above the upper EAV of 85 dB(A) employers will have to carry out a noise assessment to measure the levels precisely, but without doing an assessment how can they know if mandatory action values have been exceeded?
The following rule of thumb is based on normal conversation and gives an idea of likely noise levels:
|Test||Probable Noise Level||A risk assessment will be needed if the noise is like this for more than:|
|The noise is intrusive but normal conversation is possible||80dB||6 Hours|
|You have to shout to talk to someone 2m away||85dB||2 Hours|
|You have to shout to talk to someone 1m away||90dB||45 Minutes|
It may be difficult to estimate average exposure, perhaps because of complex work patterns or because the noise from machines is intermittent. In this case measurements should be taken, especially if the exposure level is likely to be above 85dB.
Equipment up to the job
Two pieces of equipment can be used for this; a sound level meter (pictured) is primarily designed as a hand held device used by an operator, while the noise dosimeter is worn by the staff member for his or her working shift. So, which one is best for your application? A common misconception is that if you have to measure noise doses you use a dosimeter, but in fact the preferred method of measurement for noise surveys is a sound level meter; when performing the assessment with a sound level meter the operator is present to ensuring high quality measurements that are repeatable.
A small club (250 occupancy) faced the need to respond to a noise assessment in order to continue to operate as a live music venue. After taking specialist advice a number of changes were made:
- The small triangular stage was moved from a corner and rebuilt as a slightly larger rectangle against a sidewall;
- The bar was moved from the music area into a different room;
- Sound absorbent panels were fixed to the walls and ceiling around the stage and additional sound absorbent panels were mounted in other parts of the room;
- The monitor speakers on stage were lifted off the floor and directed towards the musicians;
- A new sound distributing loudspeaker system was installed with four speakers mounted over the audience;
- Acoustic screens were provided around the drums;
- The house technician was trained in sound level measuring techniques.
- Noise measurements showed a significant reduction. Musicians, staff and audience were asked for their reactions to the changes and all very positive. The total venue noise levels were reduced from 110dB to 100dB.
With a sound level meter a representative measurement is made for each task, and with the exposure time recorded the 8 hour exposure can be calculated. The more complex the work pattern of an employee, carrying out different tasks in different locations, the more difficult and complex it is to calculate the dose using sound level meter readings. It may not be possible at all in some situations where individuals have extremely complex and diverse working patterns such as bar staff. In this case a noise dosimeter such as the CEL-350 dBadge (pictured below) is the best equipment for assessing a noise dose. The CEL-350 incorporates an exposure alarm that uses an ultra-bright LED to give an early visual indication if an individual will exceed the action values based on the current noise exposure.
Once a noise assessment establishes that there is a problem, personal hearing protection should be used as an interim measure while other more permanent technical, engineering or organisational solutions are put in place if noise levels are likely to be at the Upper Exposure Action Values. Personal hearing protection should be considered as the primary solution only when all other options have been exhausted.
The regulations only require hearing protection to be worn by workers when, despite other controls in place, their average daily or weekly exposure is at or above 85dB (A). Many things that can be done to reduce their average daily dose, such as physically separating staff from the noisiest areas or rotating jobs or shifts to spread the level of individual exposure. When noise levels make hearing protection mandatory there are many discreet options including in-ear monitors, flat response earplugs for musicians, or normal earplugs for those who do not need to hear the music. Headsets have their place too, and can combine communications capability with noise reduction for security and supervisory staff.
Managing volume levels is critical and this is achieved by keeping equipment in good working order, making it clear who can set volume levels, and training key members of staff how to use a noise meter. Direction control means pointing the sound with directional speakers to where you want it, such as onto the dance floor or performance area. The physical separation of staff from the noisiest areas and controlling the acoustic properties of the premises are more to do with the design of premises and should be built into new or refurbished venues. A leading noise consultant carried out the refurbishment of two nightclubs that initially had virtually no acoustic absorption in them. The average daily personal noise exposure of the 16 staff was reduced from 90 dB(A) to 81.5 dB(A) by a review of the layout and improved acoustic design.
Sometimes it’s the equipment that needs checking!
Another nightclub in Warrington was excessively noisy because of a lack of maintenance of the sound system, which was being driven hard to overcome its shortcomings. Dance music is perceived as having energy due to high, clear and crisp levels of low frequency or bass sound, and because the system was producing little bass frequency sound the overall levels were increased to compensate. This had the effect of increasing the more effective mid and high frequencies bringing the total sound on the dance floor to an almost painful level.
The solution was to replace all the bass driver units, clean the filters on the main amplifiers to ensure adequate cooling, equalise the system in one-third octave bands and re-set the limiter. As a result the staff had their noise exposures reduced by up to 8dB, and the noise control work had the additional benefit of creating a clean sound system which the patrons believed was even louder due to the higher cleaner levels of bass.
It is important to work with staff, monitoring those most at risk with regular health checks and informing and training them to meet noise management objectives. They must know how to use the right type of hearing protector whenever conditions demand, and it is important that they realise how rapidly the safe dosage can be exceeded in high noise environments.
Like the smoking ban, the noise regulations in the UK are designed to protect staff who work in potentially damaging environments rather than to erode the freedom of customers. Striking the balance has been a challenging task, and the Music and Entertainment Sector Working Group, which consulted on the legislation, offers specific advice (www.soundadvice.info) for all venues offering any kind of amplified music or entertainment.
Published: 10th Jul 2008 in Health and Safety International