Hearing Tests

Workers in the building and construction industry are often exposed to loud noise, either from the equipment they are using or from equipment being used by other workers nearby. The level of noise commonly found on building and construction sites has been shown to cause permanent hearing injury in workers who do not regularly use hearing protection.

Because of the high risk of hearing injury, building and construction workers are required under the Occupational Health and Safety (Noise) Regulations 1992 to have a hearing test within three months of starting work, and every two years after that. Also, a hearing test must be done when it has been reasonably requested by a Health & Safety Representative, for example, if a worker spends most of their time in the plant room, which is extremely noisy, they may need to be tested every year.

Regular hearing tests identify signs and symptoms of hearing injury, warning the worker that their current PPE use is inadequate. The hearing-screening test that you have is a check of the softest sounds that you can hear, over a range of sounds that are important for understanding speech.

Speech sounds differ in their loudness and pitch in normal conversation. Some sounds, like 'f' and 's' are high in pitch, and not very loud (about 30-40 dB) at normal speech levels. People with a noise induced hearing loss will find these speech sounds harder to hear, especially if there is background noise.

Sounds like 'ee' or 'ow' are low in pitch, and relatively louder in the way they are produced in normal level speech. This makes these sounds easier to hear, even if you have a more severe hearing loss and there is background noise present. This is why people with a noise related injury, when listening to a group conversation, or if there is background noise, can hear people talking (the 'ee' and 'ow' sounds), but can't understand what is being said (the 'f' and 's' sounds).

The test should be carried out in a sound reduced test booth or caravan by someone who is properly trained in audiometry. It is also important to ensure that you have not been exposed to excessive noise for 7 hours before the hearing test.

The results from your hearing test are a record of your hearing threshold levels. It is these results that are used to determine the level of your hearing loss.

If you have normal hearing, the hearing threshold levels for both ears at all frequencies should be less than, or equal to, 20 dB. If your hearing levels are greater than 20 dB at any frequency, you have a hearing loss at that frequency.

Generally, noise induced hearing injury causes your hearing levels to deteriorate between the frequencies of 1000 Hz (1KHz) to 8000 Hz (8KHz).

You should be given a printout of the hearing test results, or an audiogram (a graph of your hearing test results). If you are not given either of these, ask for one, and store it for future reference. The important things to check are:

• Are your hearing threshold levels at any frequency greater than 20dB?
• Has there been any deterioration in your hearing levels when you compare this test with the results of your last test?

If your hearing levels have deteriorated at any frequency, then you should have a more detailed test by an audiologist to find out what has caused the change in your hearing. An audiologist is a university trained health care professional who specializes in the assessment and management of hearing loss. An audiometrist also assesses hearing loss, but they have either a TAFE qualification, or they have received training from their employer. Audiometrists are not university qualified. So it is important that you go to an audiologist for a more comprehensive test if the audiometrist finds a change in your hearing.

If you have further noise injury, the type of ear protection you are using, and how you are using it, needs to be reviewed. If the change in your hearing is due to ear disease or ear infection, you will be referred to the appropriate person for further treatment.


All the frequencies of sound that are important for understanding speech are checked in a hearing test, and the results are recorded on an audiogram or sound graph.

The horizontal axis of the audiogram, that is, going across the chart, shows the frequency or pitch of the sounds. This ranges from 250 Hz, which is a very low frequency sound, to 8 KHz, which is a very high frequency sound. This covers the range of sound that you need to understand speech.

The vertical axis of the audiogram, that is, going from top to bottom of the chart, shows the loudness of the sounds, which ranges from 0 to 120 decibels (dB).

When your hearing is tested, the softest sound that you can hear under headphones at each frequency is recorded on the audiogram. The symbol 'O' indicates the results for the right ear, and the symbol 'X' indicates the results for the left ear.

Sometimes your audiogram will look a bit different, but the principle will be the same. Just look for the left and right ears' scores on the axis that shows the loudness of sounds, that is, the one that ranges from 0 to 120 dB.

On the chart below you can see that the hearing threshold levels for both ears at all frequencies are not more than 20 dB. So this audiogram shows a person with normal hearing.



On the following chart, you can see that the hearing threshold levels for both ears at 3K, 4K and 6K are more than 20 dB.

• At 3K the left ear (marked by X) is at 40 dB, and the right ear (marked by O) is at 45 dB.
• At 4K both ears are at 55 dB.
• At 6K the left ear is at 45 dB and the right ear is at 40 dB.

This audiogram shows a person with a hearing loss. In fact, this person has a notifiable hearing loss. Unfortunately, there is no easy way to tell if your hearing loss is enough to warrant compensation without seeing an audiologist. When you have your hearing test, make sure you ask the audiometrist/audiologist whether or not your noise injury is enough to make a compensible claim.

Julie Reid

If any member requires further information regarding occupational rehabilitation please contact the union office.