Earplugs are available that are custom-moulded to the shape of an individual’s ears. Such earplugs when used as personal protective equipment in the workplace can offer a longer life span, potential cost savings to employers and, it is often claimed, an improved level of protection and comfort compared to other forms of hearing protection. A study of a selection of CE-marked custom-moulded earplugs available in the UK was carried out in order to examine the protection provided by such devices, and to identify any influencing factors on protection, comfort and fit.
Five models of earplug were subjectively tested using either six or seven subjects. Apart from one poorly performing self-moulded earplug, the plugs provided attenuation (SNR values) in the range 16 to 24 decibels. Levels of protection for all plugs were lower than indicated by manufacturers, and statistical analysis suggested that three of the earplug models were not adequately represented by the manufacturer’s attenuation data. There was no evidence to support the view that custom-moulded earplugs provide improved levels of protection compared to other forms of hearing protection. When checked against the labelling and information requirements of the relevant product standard, BS EN 352-2:2002, only one of the models completely satisfied the requirements of the standard. A variety of information was missing including attenuation data and fitting instructions.
This report and the work it describes were funded by the Health and Safety Executive (HSE). Its contents, including any opinions and/or conclusions expressed, are those of the author alone and do not necessarily reflect HSE policy.
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