• Self;
• Competent person;
• Industrial association, insurance company or risk assessor; or
• Acoustical consultant

A simple visual and aural assessment may be required if the noise is from a single source and is obviously loud. There are often simple changes you can make to significantly reduce the noise, such as removing the noise source or enclosing it.

Where noisy equipment is used at various times for various periods, a visual and aural inspection may not be sufficient to determine levels of noise exposure.

However, a simple noise assessment can be done in many cases using a noise meter. Readings should be taken where people actually experience the noise and not at the source of the noise. You should then estimate the total period of time people are exposed to the noise during the day.

Next, follow the principle that for each 3dB(A) increase in noise level, you should halve the allowable noise exposure time. For example, an employee exposed to a continuous noise level of 88dB(A) will exceed the allowable eight-hour equivalent of 85dB(A) in four hours.

If the assessment shows unsafe noise levels, there may, again, be simple modifications you can introduce to reduce noise exposure, e.g. a noisy compressor may be replaced with a quieter one, it may be modified or properly maintained to reduce noise levels or enclosed.

In situations where noise problems are complex and pose a high risk to significant numbers of staff, it is advisable that you consider obtaining a professional assessment.

Consultancy firms will carry out a noise assessment for a fee. Firms providing this service are listed in the Yellow Pages telephone directory under the headings “Acoustical Consultants”, “Noise Control Equipment” and “Hearing Conservation Consultants &/or Services”. They should be competent and have adequate experience and knowledge of:

• the objective of assessments (ie to help you to reduce noise exposure and protect the health of your employees);
• the correct way of using instruments and their limitations;
• the analysis, interpretation and recording of results;
• the normal operating conditions of the workplace, and
• relevant Australian Standards and statutory requirements.
  Some workplaces have larger noise exposure problems than others and the methods they need to adopt to assess the noise may vary.