Audiometry Screening is carried out if there is a risk of excessive noise exposure in any job. The need for audiometry will have been identified by an occupational noise survey. Identified employees will be asked to complete a heath questionnaire specifically about their ears and hearing e.g. Have you ever had a perforated ear drum?
The occupational health professional will then examine your ears by looking into your ear canal and checking for any visual damage to the ear drum, inflammation of the ear canal or build-up of wax.
You will then be fitted with a set of earphones and given a buzzer which you will be asked to press when you hear the sounds. You will be tested on both ears and will be informed when the test is complete.
The machine will then calculate its findings and produce your results. Your hearing results will be categorised in accordance with the HSE categorisation as follows:
- Cat I-acceptable hearing ability (hearing within normal limits)
- Cat 2-mild hearing impairment (stable NlHL)
- Cat 3-poor hearing (new or progressive possible NIHL)
- Cat 4-rapid hearing loss (reduction of hearing level of 30dB or more in within 3 years or less)
- Depending on your result the following actions will be taken:
- Cat I -no action is required
- Cat 2-warning level and you will be advised to protect your hearing as much as possible
- Cat 3 & 4-referral level: you may be referred to either your GP or an occupational health physician
Effects of hearing loss
The first symptom of noise induced hearing loss is usually difficulty in hearing conversation against noisy background. The sufferer comes to dislike parties where everyone is apparently chattering away happily, yet the sufferer hears just a jumble of noise.
Consonants seem to be lost first. Often the sufferer will mention intermittent high-pitched ringing in their ears but this is rarely sufficient to be more than an irritant. By the time these symptoms have become sufficient to prompt medical consultation the damage has already been done.
Sources of induced hearing loss
Noisy machinery that is used in heavy productive industries, such as metal work, drilling, quarrying and stone cutting can cause hearing loss.
Noise above 90dB is likely to cause damage to a proportion of the exposed population with continued exposure. Very high levels may cause damage after a relatively short period even when intermittent.
This may be illustrated by the frequent finding of hearing loss in individuals who have fired guns as an occasional hobby. Individuals who are exposed to noise at lower levels but more constantly such as those working on construction sites can also suffer from hearing loss.
