Controlling hazardous noise in the amusement device industry fact sheet
In the amusement device industry, hazardous noise generated by the audio and music systems that are “turned up” to compete with other rides in attracting patrons has been identified as a work, health and safety problem.
Noise monitoring of rides undertaken by WorkCover NSW at the 2014 Sydney Royal Easter Show found that:
- hazardous noise is produced by the music – not the ride itself
- almost 75% of the music exceeded the noise exposure standard over an 8-hour period
- peak noise levels of music up to 118.4 dB(C) were measured on some rides.
Workers exposed to hazardous noise can develop permanent and irreversible hearing loss and/or other damage e.g. tinnitus (permanent buzzing or ringing in the ears).
The acceptable level of noise that a worker can be exposed to in the workplace is 85 decibels (dB) averaged over an eight-hour period (referred to as dB(A)). Everything above this is considered hazardous noise. A good rule of thumb is: If you have to raise your voice to be heard, the noise level is probably 85 dB(A) or more.
The impact of increasing noise
Zero decibels (0 dB) is the quietest sound audible to a healthy human ear. From there, every increase of 3 dB represents a doubling of noise intensity. For example, noise measured at 88 dB(A) is double the intensity of noise measured at 85dB(A).
Noise is cumulative, eg if one amusement ride emits a sound level of 91 dB(A) and a second amusement ride is placed beside it that emits exactly the same sound level, then the combined sound level is 94 dB(A), not 180 dB(A).
The separate carnival ride areas in various theme parks and agricultural shows can often create complex conditions for exposure to noise, due to the high number of amusement devices grouped together in one small area.
Noise exposure risks are cumulative. It is important to note that shift durations of 10 hours or longer present an increased risk of injury, and this risk may increase further if there is reduced recovery time between successive shifts.
Who is responsible for controlling hazardous noise?
Those who own or operate amusement devices must ensure that their amusement ride operates below the noise exposure standard.
Those involved in the management or control of workplaces must also ensure that all amusement rides operate below the noise exposure standard so far as is reasonably practicable. SafeWork NSW recommends that this requirement should be included into documented contractual agreements with all ride owner/operators. The person conducting the business or undertaking (PCBU) involved in the management and control of workplaces should also suitably plan the location of each amusement ride, so that noisy rides are not located too close together.
All involved in the event must, so far as is reasonably practicable, consult, co-operate and co-ordinate activities with each other.
Workers have a duty to take reasonable care for their own and others health and safety and cooperate to make the workplace safe. This includes following WHS policies and procedures and wearing hearing protection if provided.
Practical noise control solutions
Noise levels are controllable and some measures are more effective than others at controlling hazardous noise. The Work Health and Safety Regulation 2017 requires the use of the highest level of control that is reasonably practicable, using the hierarchy of control. The aim is to reduce the ride’s noise level, including the music, down to below or equal to 85dB(A).
In the amusement device industry, substitution and engineering controls are usually the most effective control measures to implement.
Reduce the volume, eg look at the possibility of substituting to smaller amplifiers. Using quality amplification and speakers that operate without distortion is preferable to operating inferior systems at loud levels.
Reduce the volume, eg:
- install noise limiters or compressors either within the sound system or externally. There are two main types of noise limiters:
- microphone controlled
- electronic in-circuit devices
- enclose or partition off the ride operator booth / enclosure with glass or perspex
- mount noisy or vibrating floor standing machinery and equipment on rubber pads to reduce vibration noise
- install flexible acoustic screens or curtains of sound absorbent material to reduce the exposure to noise from particular loud sources, e.g.: as a partition between two adjacent rides.
Administrative controls and personal protective equipment (PPE) are the least effective and the least reliable controls and must only be used for any leftover risk that cannot be controlled by the above controls. Administrative controls and the use of PPE rely solely on human behaviour and require constant supervision.
- Check the noise levels of machinery before purchase. Trial equipment where possible.
- Do not position several noisy rides together in one area – spread them out across the whole site, where possible.
- Rotate workers to limit their exposure to loud noise by assigning them to work shorter shifts, so that each person's daily exposure to noise is reduced, eg a worker’s shift could be split into 2 hour lots, rotating between “noisy” and “quiet” areas. Where shifts are longer than 8 hours, extreme care must be taken to ensure their exposure to any hazardous noise does not exceed safe limits as detailed on page 13 of the code of practice – Managing noise and preventing hearing loss at work.
- Specify a maximum noise level in contracts, which must not be exceeded by all, to create a level playing field.
- Position loudspeakers to avoid excessive noise levels for ride operators. Where a number of loudspeakers are positioned around an amusement ride area, consider the direction and volume from each group of speakers.
- Maintain equipment.
Personal protective hearing equipment (PPE)
Personal protective hearing protection is always the last resort because it merely attempts to protect the workers hearing – it does not prevent exposure to hazardous noise. PPE can fail or be inefficient without it being visibly obvious. Hearing protection only works when used, and its effectiveness is also reliant on its condition and whether it is fitted correctly.
If PPE is provided the owner/operator responsible must provide adequate supervision, training and instruction to their workers in the correct use and maintenance of the PPE. They must also make sure that the workers understand that they have to wear the PPE provided and wear it correctly. Regular supervision must also be undertaken to ensure that workers are wearing their PPE.
If personal hearing protection is required, the owner/operator responsible must make sure it is appropriate for the noise level and the worker. Any PPE used for noise protection should be approved in accordance with relevant Australian Standards and selected in consultation with workers or their representatives.
In order to get the full protection, workers must wear their hearing protectors at all times during a noisy shift. If they remove them, even for a short duration, their protection will be substantially reduced.
Legislation, codes and standards
- Work Health and Safety Regulation 2017
- Code of practice: Managing noise and preventing hearing loss at work
- AS/NZS 1269.1:2005 Occupational noise management—Measurement and assessment of noise immission and exposure
- AS/NZS 1270:2002 Acoustics – Hearing protectors.
Contacts and assistance
- Visit the National Acoustic Laboratories (NAL) website or call them 9412 6800
- Visit the Australian Amusement, Leisure and Recreation Assoc Inc website or call them on 1800 118 123.
Catalogue No. WC01668