Exposure to excessive levels of noise may lead to noise induced hearing loss. This page includes basic information about noise, hearing loss and steps which can be taken to prevent hearing loss.

Services Provided


Occupational Health and Safety will conduct noise surveys in areas where the potential for noise has been identified. If there is a concern about noise levels the area supervisor should contact OH&S to arrange for a site visit. Contact to arrange for this.

Hearing Protection:

Western Occupational Health & Safety in Room 4159 in the Support Services Building carries a selection of hearing protectors for personnel exposed to noise. A selection of ear plugs can be picked up and tried, so the most suitable one for the user can be selected. Ear muffs are also available for purchase at cost by the user department.

Audiometric Testing:

Staff / Faculty Health Services will arrange for audiometric testing of those individuals exposed to noise levels in excess of 85 dBA.

Western Hearing Protection Program

The purpose of this Hearing Protection Program is to ensure that the hearing of University employees is continuously protected. The program includes strategy to identify noise hazard areas, and implement measures to protect all employees who have the potential to develop occupational noise-induced hearing loss.

Basic Definitions


A method of hearing assessment which tests an individual's ability to hear sounds of different intensities and frequencies. Audiometry detects early, asymptomatic noise-induced hearing loss before the affected individual is even aware that it is happening.


The decibel is a logarithmic and dimensionless unit for measuring sound pressure levels.

A-weighted decibel:

The A-weighted decibel or dBA, is a type of decibel measurement which closely represents the manner in which a human ear responds to noise.

Exchange Rate:

The increase (decrease) in sound level for which permissible exposure time is halved (doubled). The two common exchange rates are 3 dB and 5 dB.


In general, noise is considered to be any unwanted sound.

Noise dosimetry:

This noise assessment technique measures an employee's personal noise exposure and is particularly useful and applicable when employees work in numerous noisy areas for short durations at a time or perform different noisy operations on any given day.

Noise hazard area:

An area is considered a noise hazard if the sound levels regularly exceed 85 dBA.

Noise surveys:

Noise surveys provide valuable information regarding sound levels in an area. The most common type is a general noise survey which measures sound levels in A-weighted decibels (dBA).

Time-weighted average:

The time-weighted average (TWA) represents the average (noise) exposure measured over a typical 8-hour workday.

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