On April 6 the Control of Noise at Work Regulations 2005 will come into effect for any licensed premises or venue offering amplified music entertainment. Tim Turney, Product Manager with Casella CEL which manufactures noise measuring and dose meter technology takes a quiet look at the noisiest industry in town.

When the smoking ban came into effect last June many clubs and pubs held a ‘farewell to smoking’ evening to mark the cigarette’s last gasp. When the new Control of Noise at Work Regulations 2005 come into force on April 6 they may not receive the same noisy fanfare as the smoking ban, but their impact on many licensed premises could be just as great.

Designed to protect staff from hearing damage in noisy working environments, the legislation came into effect in 2006 for everyone but the music and entertainment business, which was given an additional two years before enforcement to meet the challenge. How can pubs, clubs, hotels and even the big rock concert venues keep the noise exposure of their staff to within the new legal limits without cranking down the volume for their patrons?

Hotels, clubs and venues which host occasional functions with discos and live bands may have the most difficulty gauging and managing staff exposure levels. Whilst their clients, the event organisers, may be responsible for the event going well and everyone having a good time, they are not responsible for the venue’s compliance with health and safety legislation nor the safety of its workers.

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 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 Lower Exposure Action Value (LEAV) is set by the legislation at an 8-hour average exposure level (or daily personal noise exposure level, LAEP,d) of 80 dB(A). At this level the employer has to provide information and training to staff, and make hearing protection available. The Upper Exposure Action Value (UEAV) is set at a LAEP,d of 85 dB(A), and above this the employer must measure levels precisely and take action to reduce it; if you have to shout to communicate with someone 2 metres away the probable noise level is 85dB.

The Royal National Institute for Deaf People (RNID) carried out a covert survey in 2004 of 15 city nightclubs across the UK and found that even in chill out areas where they were provided, the noise levels averaged 92.3dB(A), 12 decibels higher than the lower exposure action value. Levels could get as high as 110dB(A) and at this loudness staff will receive their legal daily dose of noise in a matter of seconds.

As important as loudness is the duration of exposure, and moving bars away from the source of the noise and rotating shifts to spread exposure can help. Controlling volume means keeping equipment in good working condition, making it clear who can set volume levels and training a member of staff to use a noise meter. Controlling the location of the noise means pointing the sound where you want it, such as onto the dance floor or performance area with directional speakers.

The physical separation of staff from the noisiest areas and changing the acoustic properties of the premises are more to do with the design of the premises and should be considered when refurbishment work is planned. 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) through a review of the layout and improved acoustic design.

A sound level meter is the basic tool for an assessment, while the noise dosimeter is worn by an employee to measures their dosage during the course of his or her working shift. The preferred tool for noise surveys is the sound level meter because the operator is present to ensure that good quality measurements which can be repeated in subsequent tests are taken. A representative measurement is made with a sound level meter for each task and the exposure time recorded, and the 8 hour exposure can be calculated from this.