LISTEN! You might be going deaf OCCUPATIONAL SAFETY & HEALTH SERVICE 1 DEPARTMENT OF LABOUR TE TARI MAHI
GET THE ANSWERS ABOUT HOW NOISE AFFECTS YOU. Issued by the Occupational Safety & Health Service, Department of Labour, Wellington, New Zealand 1996 2
WHEN IS NOISE LIKELY TO HARM MY HEARING? A: The risk of damage to your hearing in the work place depends on how loud the noise is and how long you are exposed to it each day. Noise starts to be a hazard when it means you have to raise your voice to speak to someone about a metre away, or when it is about as loud as heavy city traffic. At noise levels below this, you can work all day with little risk of hearing damage. However, the best way to judge whether a workplace is noisy enough to be hazardous is to have its noise levels measured by a trained person. 3
HOW COULD HEARING LOSS AFFECT ME? A: It reduces your quality of life by making it difficult for you to understand other people. It can stop you communicating properly with your family and friends, listening to your favourite music or comfortably watching TV. At work it can be dangerous if you are unable to hear instructions, warning sounds or calls. You could also suffer from ringing, buzzing or whistling sounds in your ears. These sounds can be extremely disturbing and interfere with your sleep. 4
HOW FAST CAN HEARING LOSS HAPPEN? A: Daily exposure to very loud noise can cause permanent hearing damage in just a few months. Noise-induced hearing loss is not something that happens just to older people. Many people in their early twenties also suffer work-related hearing loss. 5
IS THERE A CURE FOR HEARING LOSS? A: No. Noise-induced hearing loss is permanent. It can t be cured. Noise kills off the delicate inner ear hair cells that transmit sound impulses to your brain. Once they die, they can t come back to life. Hearing aids are of limited use. 6
HOW CAN I BE PROTECTED AGAINST HEARING LOSS? A: The best protection is to reduce workplace noise to safe levels. Often noise can be reduced simply and inexpensively. Organisations should systematically reduce noise by modifying existing noisy equipment and purchasing quieter equipment in the future. Achieving safe noise levels, however, can take time sometimes years. So, while the necessary changes are being made, it s necessary to protect your hearing with earplugs or earmuffs. 7
WHOSE RESPONSIBILITY IS IT TO REDUCE NOISE AND PROTECT MY HEARING? A: The Health and Safety in Employment Act requires employers to control noise hazards that could damage employees hearing and reduce noise to safe levels. Where noise cannot be immediately reduced to safe levels, employers must provide hearing protection to exposed employees. Employees must follow work safety instructions and use hearing protection equipment when required. Employers and employees should work together to reduce noise in the workplace. 8
WHAT SHOULD I DO IF I THINK MY HEARING IS ALREADY AFFECTED? A: See your doctor for a hearing test. This will show if you have a hearing loss and will help determine whether it is caused by noise exposure or some other medical condition. The test alone will not be able to tell you if you are at risk in your current work. 9
WHAT SHOULD I DO IF I THINK I AM AT RISK? A: If you are worried about noise in your workplace, or you have been advised that you already have a noise-induced hearing loss, speak to your employer. Your employer is required to identify noise hazards in the workplace. If noise levels exceed the limits stated in the Health and Safety in Employment Regulations, a programme should be set in place to manage the problem and protect the hearing of you and your fellow workers. As part of this programme, your employer should provide hearing tests to identify employees whose hearing is being damaged. Your employer must have your consent to carry out these tests and any subsequent tests to monitor your hearing. The results of the tests must be explained to you. 10
Until noise levels are made safe, make sure Q: you always wear hearing protection when exposed to high noise levels. Your employer is required to provide suitable hearing protection and to train you in its use, care and maintenance. You can get further help and advice from: an occupational health nurse, or a health and safety inspector. You can contact them at your nearest Occupational Safety and Health Service office (listed under Labour Department in the telephone book). 11
LIKE TO KNOW MORE? HERE ARE THE DETAILS What is sound? Sound is generated when a noise source e.g. a voice or a machine vibrates the air around us, creating pressure waves. Its strength is measured in decibels, db for short. People with normal hearing can hear sound levels between 0dB (the hearing threshold) and 120dB (the pain level), or more. Here are some typical noise levels in decibels (db): Type of sound Decibels Rustle of leaves 10dB Average whisper 25dB City street 50 to 85dB Average factory 70 to 110dB Circular saw100 to 115dB Drop hammer 100 to I30dB Jet engine l40db How does hearing work? The ear receives sound waves which are funnelled into the ear canal. The eardrum catches them and passes them into the inner ear through the ossicles, which make them stronger. Tiny hairs in the inner ear are bent back and 12
forth in response to the waves and send electrical Q: signals to the brain through the hearing nerve. In the brain, the signals are deciphered so that we hear the sound. After too much noise, the hair cells in the inner ear become fatigued, and need time to recover. During that time, your hearing becomes temporarily dulled. If the hair cells are too stimulated, or don t get enough rest, they will, after a time, die. Can noise really be reduced in most workplaces? In many ways, a lot of unnecessary noise occurs in workplaces. There are often ways of doing tasks less noisily, for example metal can often be shaped by bending or pressing rather than a noisier hammering process. Noisy machines can be quietened by enclosures or partitions to separate the operators from the noise source. Sometimes the machine can be modified, or be fitted with silencers to reduce noise emissions. Such changes should be part of a total programme to manage noise problems in a workplace. The organisations should consult employees and their representatives in establishing such programmes. Operators should be encouraged to contribute ideas about how noise could be reduced. 13
What kinds of hearing protectors are Q: available? The two main kinds are ear muffs and ear plugs. There are many designs of each, and some types of ear plugs are made in a range of sizes. It is worth trying several protectors to find the one that suits you best. The main points to look for are comfort, convenience and compatibility with the job and any other head gear that has to be worn. Remember, hearing protectors are only a temporary measure in managing noise problems, not a solution. Noise must be reduced to safe levels wherever possible. Aren t hearing protectors uncomfortable? Hearing protectors may feel uncomfortable when first worn. It can take a little time to get used to them, after which you will appreciate the peace and quiet they create. If, for any reason, they remain uncomfortable, seek advice and try another type until one is found that suits you. Is there any danger in putting plugs in my ears? Ear plugs are soft and their design makes it virtually impossible to sustain any harm wearing them. However, you should always use them 14
hygienically, washing your hands before inserting or removing them. Q: Will I be able to hear what other people are saying if I wear hearing protectors? In fact, if your hearing is normal, you will actually find it easier to hear what others say. With hearing protectors, your ears are not overloaded with noise. It s like wearing sun glasses you see better when the glare is reduced. What about protection at home? Use hearing protection at home, too, when you use power tools like saws, grinders, motor mowers, chainsaws, etc. as well as limiting your exposure to very loud music. Which are better earplugs or earmuffs? There s no easy answer to this question. Earmuffs are generally more reliable as they are less dependent on careful fitting. Earmuffs, however, tend to be less comfortable in hot environments. Once a range of types of hearing protection has been selected as suitable for the particular work environment or task, it is the user who ultimately must decide which form of protection is best suited to his or her needs. 15
FURTHER INFORMATION The Occupational Safety and Health Service has other pamphlets on noise-induced hearing loss and its prevention. Other resources to help organisations to manage noise effectively are: Approved Code of Practice for the Management of Noise at Work. Sets out the preferred work practices that will assist employers to meet the requirements of the Health and Safety in Employment Act 1992. Price: $10. Control Guide: Management of Noise at Work. A comprehensive information package on setting up and running a programme to buy quiet, control noise at source and manage personal hearing protection. Price: $100. To order, contact your nearest office of the Occupational Safety and Health Service (listed in the telephone book under Labour Department). OCCUPATIONAL SAFETY & HEALTH SERVICE DEPARTMENT OF LABOUR TE TARI MAHI