Hearing Protection

Ian Paterson, Vice President, Tinnitus Association of Victoria

The aging process causes a natural hearing decline in almost everyone, particularly those living in a westernised society with its many sounds that are heard each day such as machinery, cars, television etc.

This decline in our ability to clearly hear affects mainly high pitched sounds such as children's voices, rustling leaves and some musical instruments.

Although 'age effect' hearing loss up through the age of 60 does not usually impair one's ability to hear and understand speech, problems occur when noise induced loss is added to the age loss. With noise damage, even a thirty year old can have trouble listening when background sound is present, such as in restaurants or crowded social environments.


You do not 'get used to noise'

Noise does not have to be uncomfortably loud to be damaging. You may even think that after working or living with a certain level of sound, your ears are 'used to it', but what has happened is that hearing loss has already begun. How quickly hearing loss takes place depends on the intensity of the noise, its duration and how often the exposure occurs.

When you need to shout to be heard when you are one meter away, the noise levels are probably above 85dBA and hearing protection is recommended.


Noise damage indicators

If sounds seem muffled or softer after noise exposure, your hearing has been affected by a temporary threshold shift, which warns that your hearing has been overexposed. If you repeatedly do this without protection, the shift can become permanent and untreatable.

For those of us with tinnitus, even temporary exposure to loud sounds can be the equivalent of 'sunburn of the hairs in the cochlear'. This means that your tinnitus will be elevated either for a short time (minutes to weeks) or result in a permanent elevation of your tinnitus level. It is critical that you protect your hearing whenever you are doing anything that exposes your ears to any sound louder than a domestic vacuum cleaner.


Hearing Protection Devices

There are 4 main types of hearing protection, they are: Formable Plugs, Premolded Plugs, Semi-aural Devices and Ear Muffs. When selecting any hearing protection device, make sure you purchase quality products only; selecting something on price alone could cost you your hearing. It is best to purchase these types of products from an industrial safety supplier where you can get quality products and expert advice.

They are listed in the yellow pages under that classification and available in most metropolitan and country regions.

Always check the dBA rating of hearing protection products. As sound is measured logarithmically, be aware that when comparing two products of say, 30dBA and 33dBA, that the 33dBA product is not just ten percent better than the 30dBA product, it is twice as effective. Most earplugs are about 25 dBA and good ear muffs start at about 28dBA and go up to 34dBA. A good practice is to have a couple of pairs of disposable ear plugs in your car / handbag as well as at home and at least one pair of ear muffs where you would normally expose yourself to loud noise such as in the garage. Good quality hearing protection devices allow you to hear conversation around you, but cut out the harmful peaks of sound.


Fitting Hearing Protection

For hearing protection devices to be effective, they must fit correctly and be worn correctly, i.e. formable plugs must expand to fully block the ear canal and must be in the ear and not just sitting on the outside.

To correctly insert earplugs, slowly roll and compress the plug into a thin cylinder or to the shape of a golf tee without inducing creasing. While the plugs are compressed, insert it well into the ear canal and hold it there while it begins to expand.

Fitting is easier if you reach around the head and pull the ear outward and upward during insertion. Some earplugs can be washed in warm soapy water and reused, however do not re-use plugs that are cracked, hard or do not readily expand to their original size. If the plug bends, creases or deforms during insertion, remove it, reform it and then re-insert it. When fitted correctly, the outer edge of the earplug should be flush with or slightly inside the Tragus with at least half of the plug being inside the ear canal.

A rough test of whether an earplug is inserted correctly can be applied by cupping your hands over your ears while listening to a steady noise. If the plugs are fitted correctly, the noise levels should be almost the same whether or not you are covering your ears.

Earmuffs must fully enclose the ears and seal against the head. Adjust the headband so that the cushions exert an even pressure around the ears making sure that hair is pulled back from under the cushions.

If you wear glasses, make sure that you choose earmuffs that have deep soft cushions that will mould around the stem of the glasses to form a firm fit against your head.



At What Noise Level Should I Use Hearing Protection?

As a guide, a motor mower is about 80dBA and this is about the threshold above which a person with no auditory problems must protect themselves, particularly as the duration of the exposure lengthens. The higher the level of sound, the shorter the time that you can be exposed before damage occurs. The chart in appendix 6 shows the relationship between the level of sound and the maximum allowable exposure for someone without any auditory problems or tinnitus. This should be taken as a guide only and someone who has tinnitus should always protect themselves from sounds of 80 - 85dBA or above.

It is better to err on the side of safety and protect your ears in all situations that you think may exacerbate your tinnitus; such as using a power tool, hammer, mowing the lawn, a noisy vacuum cleaner etc. The few seconds that it may take to put on a set of ear muffs may save you many hours of discomfort.

Hearing Protection