Sound Advice Note 11

Exposure to noise

11.1 This advice provides methods of controlling the risk of hearing loss in venues where amplified music is played, including nightclubs, bars, pubs and restaurants. In most industries noise is an unwanted by-product. However, high sound levels often provide the principal stimulus for customers to attend a pub or club. It is important to remember that all employees, including any guest performers, are covered by the Noise Regulations and employers have responsibilities to protect their employees' hearing. Self-employed people should also read Sound Advice Note 7 'Freelancers'. A noise risk assessment flowchart for pubs and clubs is shown at the end of this advice note.

11.2 There is a strong likelihood that workers in venues playing amplified music will be exposed to noise levels at or above the upper exposure action value of the Noise Regulations. For representative exposure levels see the table below. Remember that no single measure will be appropriate for every situation and it is important to identify the actions that will best control the risk.

Representative exposure levels in clubs

Occupation	dB
Bar staff	89 - 99
Glass collectors	90 - 100
Waiters	102
DJs	93 - 99
Lighting technician	104
Security	97
Door	84
Dance floor	94 - 104

Design

11.3 Methods of reducing noise in work areas can be split into two categories - physical separation and focusing the music in the desired locations. Architects/designers and owners/operators proposing new buildings or refurbishments should consult competent acousticians and/or sound engineers before undertaking any major work. See also Sound Advice Note 8 'Venues'

The three components of noise

11.4 The noise in a venue is made up of three components: the direct path is the uninterrupted path between the loudspeakers and the ear, the reverberant path is the sound reflected off one or more surfaces, and the structural path is through the fixings and mountings. The careful positioning of loudspeakers may reduce direct exposure and isolation mountings may be needed to reduce structurally transmitted noise. However, many noise-control measures aim to reduce reflected sound. This may be achieved by acoustic absorption to control the reverberant paths. Note the absorption can also improve the quality of the reproduction of the music.

11.5 It is important that the materials used meet the required standards of flame retardancy and flame propagation.

Physical separation

11.6 The following techniques help separate staff from the music:

• Position bars away from the dance floor and performance areas.
• Provide staff off-duty areas with noise levels below 80 dB.
• Locate bars in quiet areas or 'chill-out' rooms where the noise levels are preferably below 80 dB.
• Acoustic screening can be helpful to protect specific workers and locations from direct noise sources, for example, technicians, bar staff, front of house. The effectiveness of screens depends on their design and location(s) which need to be carefully considered.

Focusing the music

11.7 Successful noise control requires the music to be focused where it is wanted (such as the dance floor or the performance area). The following techniques can help to focus the music and therefore reduce the noise levels away from the dance floor or performance area:

• Use equipment which avoids distortion and allows volume levels to be set lower while achieving the desired effect.
• Directional speakers can be helpful to focus sound away from sensitive areas to where it is wanted, for example over the dance floor using loudspeakers mounted in the ceiling and facing downwards.
• Increase the number of directional loudspeakers to avoid 'hot-spots'.
• Install vibration isolation mounts to loudspeakers to prevent noise entering the building structure.
• Avoid peripheral loudspeakers or reduce their volume if they cannot be avoided.
• Do not have loudspeakers pointing toward the bar or other fixed work locations.

Management

11.8 Venue operators are encouraged to develop a written noise-exposure policy. This document should aim to provide clear messages regarding the control of noise in the venue to all staff and subcontractors (see also Sound Advice Note 8 'Venues'). It should also include policies on the following:

• level setting and monitoring;
• exposure management;
• maintenance;
• information, instruction and training;
• hearing protection;
• Health surveillance.

Level setting

11.9 The exposure of employees to noise levels will depend on the volume of music played as well as the duration and proximity of the noise source. There will be instances where the volume needs to be controlled by setting maximum levels. This is usually done by the use of limiters, and many clubs and pubs will already be aware of their use for reducing noise breakout as part of the licensing procedure and local nuisance control.

11.10 Where noise-volume-limiting devices are used for reducing exposure to employees, the responsibility and ability to alter the maximum level should be clearly identified in the noise-exposure policy. The policy should also be clearly communicated to all people who have the means to adjust levels up to the maximum during events (for example duty managers, DJs, musicians and technicians).

11.11 Karaoke systems should have in-built noise limiters as they are used by members of the public who are not covered by management noise policies.

11.12 Where required, the choice of noise limiter will depend on the type of equipment to be controlled:

• Where the venue has a purpose-built amplification and speaker system the noise level can be controlled by measuring average output against a set threshold. This level cannot be exceeded and, as the quality of sound output can be maintained, there is less likelihood of public awareness of control.
• Where control of the level is not directly under the control of the management, via a purpose-built system, then the limiter will rely on a microphone picking up noise levels and if a preset level is exceeded, the power supply to the noise-generating source is cut off. This is usually done through a series of warning lights. This system requires strict management control to avoid any possible consequences of an abrupt termination. These types of limiters are often used by people in charge of venues where performers, for example guest DJs, supply their own equipment.
• All noise limiters should be tamper-proof or located in secure areas.

Monitoring

11.13 Where spot checks of the noise levels are being used as part of an assessment they should be at predetermined reference positions to allow direct comparisons between different situations. This will also allow for other representative exposure calculations to be carried out if necessary.

Example of pub/club layout showing reference positions for noise measurement

Exposure management

11.14 Managing exposure to noise could include:

• Limiting the time staff spend in noisy areas.
• Rotating staff between noisy and quiet areas and rotation between quiet and noisy shifts. Task rotation can provide some reduction in exposure where there are workstations in quiet areas. Management should have enough control and administration to demonstrate how the system safeguards staff and should explain the purpose of any rotation system to staff.
• Providing regular 'quiet breaks' and periods working in quiet areas.

11.15 The Noise Regulations allow the noise exposure to be assessed over a week rather than a day in certain circumstances (see 'Estimating noise exposure using the points system' in Sound Advice Note 3 'Noise risk assessment').

Maintenance

11.16 Sound equipment does deteriorate and should be properly checked and maintained. Note in particular there is a tendency to increase the volume if the music system is distorting.

11.17 Equipment such as noise limiters, acoustic screens, sound absorbers and vibration isolation mounts should also be kept in good working order.

Information, instruction and training

11.18 Employees need to understand the risk of hearing loss and how it is being controlled, including the proper use of hearing protection. Individuals who have influence over the noise levels (duty managers, DJs, musicians and technicians) need to understand their responsibilities.

Hearing protection

11.19 See Sound Advice Note 5 'Personal hearing protection'.

Health surveillance

11.20 See Sound Advice Note 6 'Hearing health surveillance'

Live Performers

11.21 Any venue that engages performers, such as musicians or DJs, should have a formal contractual relationship with the performer(s) and anyone else involved such as an agent or a fixer. The contract should, among other matters, identify the responsibilities of all parties under the Noise Regulations. See Contracts in Sound Advice Note 2 'Responsibilities'.

11.22 Many venues, in particular small pubs, do not issue written contracts when engaging performers. However all venues should consider this procedure to ensure that the engager/contractor and the performers are fully aware of the responsibilities of both the venue operator and the performer(s).

11.23 Visiting performers should be encouraged to use the in-house PA system rather than setting up their own temporary arrangements, which may make it more difficult for management to control noise exposure.

11.24 Between 'sets' performers should be encouraged to move to a quiet area. When arranging for live 'gigs', ensure that support acts, such as DJs, disco or karaoke, are arranged so that they will not contribute to excessive noise exposure.

Risk assessment for amplified music played in nightclubs, pubs and restaurants

Glossary

For a more detailed explanation of terms see Useful information and glossary.

Exposure action values (EAV) Levels of exposure to noise at which certain actions need to be taken (see Useful information and glossary)

Engager/contractor In the entertainment industry employers are often known as engagers or contractors. Other terms used, which may or may not imply employment, include producers, promoters, managers and fixers.

Health surveillanceFor the purposes of this guidance, ongoing assessment of the state of aural health of an employee as related to exposure to noise.

In-ear monitors Essentially earplugs with built-in miniature monitors (loudspeakers). It is essential that they are fitted with noise limiters.

Noise exposure 'The noise dose', which can be calculated, takes account of the actual volume of sound and how long it continues. Noise exposure is not the same as sound level, which is the level of noise measured at a particular moment.

Noise limiter Sometimes known as volume regulatory device (VRD), controls noise exposure from amplified music. Modern noise limiters can be fitted with anti-tamper relays connected to external switches to improve system security

PA Public address system. Sometimes called a 'Tannoy'. Often used to refer to any loudspeaker transmitting messages rather than music.

Reference position Standard location, usually static, selected to enable monitoring of noise levels to be conducted by measurements. See Sound Advice Note 4 'Noise control measures and training'.

Tinnitus Buzzing, ringing or tone in the ear. Temporary tinnitus is a warning; a sign that 'you got away with it that time.'

Upper Exposure Action Values: see Exposure action values.

VRD Volume regulatory device (see noise limiter).

Bibliography

• Control of noise in the music entertainment industry. Code of practiceWorksafe Western Australia Commission 2003 www.docep.wa.gov.au/worksafe
• The Control of Noise at Work Regulations 2005 SI 2005 No 1643 The Stationery Office 2005 ISBN 978 0 11 072984 8 (also available from www.opsi.gov.uk)
• Controlling noise at work. The Control of Noise at Work Regulations 2005. Guidance on RegulationsL108 (Second edition) HSE Books 2005 ISBN 978 0 7176 6164 0
• Listen while you work: Hearing conservation for the arts for performers and other workers in art and entertainment Safety & Health in Arts Production & Entertainment(SHAPE), Canada 2001 ISBN 978 0 7726 4643 9 www.shape.bc.ca/resources/pdf/listen.pdf
• Noise at work: Guidance for employers on the Control of Noise at Work Regulations 2005 Leaflet INDG362(rev1) HSE Books 2005 (single copy free or priced packs of 10 ISBN 978 0 7176 6165 7)
• Noise levels and noise exposure of workers in pubs and clubs: A review of the literature RR026 HSE Books 2002 ISBN 978 0 7176 2571 0
• Protect your hearing or lose it! Pocket card INDG363(rev1) HSE Books 2005 (single copy free or priced packs of 25 ISBN 978 0 7176 6166 4)