Audiometric testing
About Audiometric testing
Testing scheme
Assessment of audiograms
Action to be taken when threshold shifts are detected
About Audiometric testing
The hearing of workers exposed to noise can be monitored through regular audiometric examinations. Testing alone is not a preventive mechanism but it is an important part of managing risks from noise exposure in a workplace.
Any changes in a person's hearing levels revealed by audiometric testing should be investigated as to their cause(s) and the need for corrective action.
Audiometric testing can also be provided to workers exposed to acoustic incidents or to workplace ototoxins (chemicals which may result in hearing loss). For information on acoustic shock and ototoxins, check appendix 4 and appendix 5 of the Noise Advisory Standard 2004 (now known as a Code of Practice) .
Testing scheme
All testing should be done by an appropriately trained and experienced person, who is selected by management in consultation with workers and workplace health and safety representatives. A person who carries out audiometric testing should use procedures and equipment that comply with part 4 of AS/NZS 1269 Occupational noise management (non-Queensland Government link) .
The audiometric testing scheme should include:
- an initial reference audiometry test carried out as soon as possible after commencement of employment
- monitoring audiometry testing at 3 months and 12 months after initial work exposure for comparison with the reference tests
- monitoring audiometry testing at yearly intervals, if no threshold shift has been detected
For further information on the details of and processes for audiometric testing, check section 6 of the Noise Advisory Standard 2004 (now known as a Code of Practice) .
Assessment of audiograms
Audiograms should be assessed and action taken in accordance with section 9 of part 4 of AS/NZS 1269 Occupational noise management (non-Queensland Government link) .
If workers are found to have sufficient hearing loss to interfere with the safe performance of their jobs and their communication ability, all practicable steps should be taken to modify the work environment. Modifications can include volume control telephones, acoustically treated meeting areas with low noise and low reverberation, and supplementary visual warning signals.
Where these cannot remedy the situation, workers should be offered alternative work that does not put them at risk from excessive noise.
For further information on the assessment of audiograms, check section 6 of the Noise Advisory Standard 2004 (now known as a Code of Practice) .
Action to be taken when threshold shifts are detected
On exposure to noise above an intensity level of 75dB(A), the ear's sensitivity level will decrease. This process is referred to as a shift in the threshold of hearing. The shift can be:
- temporary, called temporary threshold shift (TTS), and recovers gradually after the noise exposure
- permanent, called permanent threshold shift (PTS), and does not recover resulting in permanent hearing loss
When temporary or permanent threshold shifts are revealed by audiometric tests or new tinnitus reported, action should be taken to inform the responsible person, employer, business owner to arrange to:
- review the worker's job to identify any changes that may have caused an increase in exposure to noise
- re-determine exposure to noise, if necessary
- check whether anything can be done to reduce the levels of noise to which the worker is exposed and the duration of exposure
- check that the performance of the worker's hearing protector is adequate for the level of exposure to noise
- examine the hearing protector carefully and ensure it is not worn or damaged
- check the worker is able to fit the hearing protector properly
- check the hearing protector fits the worker closely and there are no leakage paths
- ask the worker if he or she has any difficulty in using the hearing protector
- check the worker actually uses the hearing protector correctly and
- deal with any problems revealed by the above procedures, calling in expert advice as necessary
- Complete and submit an incident notification form (PDF, 58kB) to Workplace Health and Safety Queensland
For further information on the results of audiometric tests, check section 6, appendix 3 and appendix 4 of the Noise Advisory Standard 2004 (now known as a Code of Practice) .