Australasian Mining Review
Issue link: http://ebook.aprs.com.au/i/26056
60 T Aging causes a natural hearing decline in almost everyone, however with noise damage, even a 30-year-old can have trouble listening, writes Ian Paterson, Vice President, Tinnitus Association of Victoria. he 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 and 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 30-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 metre 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. There are four 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 10 per cent 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 and/ or 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 Hearing Protection calls for urgent exploration development initiatives