Noise limiting devices are common in nightclubs, bars, pubs, restaurants and live music venues and are often used as a way of limiting music volume. Noise limiting devices (NLDs) are used for two main reasons in the licenced trade:
- To protect the health and safety of employees on-site who are exposed to loud amplified music and, as a consequence, potential hearing loss; and
- To limit the effect of noise on neighbours and potential for nuisance.
Employees (and self-employed workers) like bar staff, security and waiters may regularly be exposed to sound levels in excess of 100dB. There are clear responsibilities placed on operators to ensure that they assess the risk that noise poses to health and put in place control measures that limit exposure. Devices that regulate volume will clearly play an important role in such circumstances; alongside other measures such as designing work areas to limit exposure.
Noise Limiting Devices – Compliance
When it comes to nuisance control the case for NLDs is not so clear. In recent years, particularly during the transitionary period of the current licensing act, it has been popular for licensing authorities to place conditions on premises licences requiring the use of a NLD. Councillors and licensing managers, often having limited knowledge of noise control and acoustics, sometimes see the NLD as a panacea to noise. In other cases they may have been used as a way of appeasing objectors. In any case, many licensing conditions specifying the use of a NLD are poorly considered and poorly worded and, as a consequence, unenforceable.
“A noise limiter must be maintained to the satisfaction of the licensing officer”.
Consider the above condition. Do they mean a volume knob? Furthermore, it would not prevent the device from being legally circumvented.
That is not to say that any operator should disregard any of their licensing obligations; on the contrary, there are a number of reasons why operators should do their best to comply.
There are also a number of other factors that should be considered by the operator when considering the installation of a NLD:
- It may lower sound quality (e.g. where amplified sound is reduced below percussive or brass instrumentation);
- NLDs may not always resolve problems associated with frequency or tonality;
- Drums and trumpets are still loud;
- Crowds are too;
- Setting a suitable level can be difficult.
Relying on a NLD to control noise can be like placing a square peg in a round hole if the building itself is not suitably constructed or designed in order to reduce noise emissions. Where located next to potential sufferers, if it is not reasonably practicable (financially or otherwise) to improve the fabric and design of the building regular (loud) music events are not recommended. Unfortunately, some community buildings and clubs attempting to subsidise their income by maximising evening events can sometimes fall into this category. Where some form of acoustic control may be provided by the venue and it’s management, the number of loud events and the time that they occur provide the best form of nuisance control. Beyond this the NLD can provide a useful contribution to the operator’s noise management plan.
Choosing and Installing
When in use a microphone monitors the sound against a pre-set level. Where the level is exceeded the NLD will provide an indication that the music is too loud and, after an extended period of exceedance, will cut off the power to the amplification equipment.
When setting up the device use a reference level inside the building that relates to a suitable threshold outside (or in a neighbouring property). Where there is a cut-off make sure that all electrically amplified equipment (amps, speakers etc.) run through the system.