Safe Work Australia released the publication “Occupational noise-induced hearing loss in Australia: overcoming barriers to effective noise control and hearing loss prevention” in August 2010. Go to document for more information.

The type and detail of noise measurements in the noise survey and the noise assessment will depend on how the information will be used.

The general objectives of the noise survey and noise assessment are to:

• Identify all significant noise sources and employees likely to be exposed to noise above specified levels. This will generally involve a walkthrough or base-line noise survey with spot noise measurements and if required personal noise dosimetry taken and the evaluation of LAeq,8h and peak noise levels where relevant.
• Obtaining information on noise sources and work practices that will help deciding what measures should be taken to reduce noise levels in the workplace.
• Check the effectiveness of measures taken to reduce exposure (Provided that a base-line has been established in a more comprehensive noise assessment, it might be possible to restrict such noise surveys to measurement of noise levels at a few defined positions and under a restricted range of working or loading conditions of the equipment involved.)
• Help in the selection of appropriate personal hearing protectors.
• Delineate hearing protection areas.
  The detail and accuracy needed will depend on individual circumstances encountered in the workplace.

The period between noise assessments should be determined by management in consultation with employees through established consultative processes. The noise assessment should be repeated at intervals not exceeding five years or whenever there is:

• Installation of new or removal of machinery.
• A change in workload or equipment operating conditions likely to cause a significant change in noise levels.
• A change in building structure likely to affect noise levels.
• Modification of working arrangements affecting the length of time employees would spend in noisy workplaces.

A noise assessment may be simple or quite complex, depending on the type of workplace, the number of employees and the information already available regarding occupational noise exposure levels.
When no prior information is available, an initial or preliminary noise survey and noise assessment is made (walkthrough Noise Survey) to establish if noise exposure is acceptable or not.

Noise measurements are to be undertaken in accordance with Australian Standards AS1269 and AS 2659. Where noise measurements indicate that hearing protection is likely to be necessary, readings in dB(C) may also be taken during the initial noise assessment in order to determine the attenuation required by personal hearing protectors. Alternatively, a separate follow-up noise assessment or detailed noise assessment may be required for this purpose.
In some cases, more complex noise measurements are required in order to determine employees’ occupational noise exposure with acceptable accuracy, or for the selection of personal hearing protectors. For example, octave band analysis of the noise may be required if the noise contains intense tonal, high frequency or low frequency components. This can also be part of the detailed occupational noise assessment.