How to choose suitable ear protection
Ear muffs are used to protect the ears from hearing damage and potential short-term or long-term hearing loss. Noise induced hearing loss is one of many hazards encountered in the workplace and because it doesn't necessarily show up as a direct injury, this doesn’t mean serious long term damage has not occurred.
Most people are not aware that the human ear can only accept a maximum of 75 decibels of noise. Workers operating Lawnmowers, Chainsaws, Drilling Machines, Grinders and large power tools are common casualties of hearing loss. This happens when protective ear muffs are not worn – even if only for seconds or minutes while operating machinery. Even short-term, irregular or frequent exposure to loud noises generated by these tools can destroy hearing over time.
There are different ear muffs for different working environments like construction sites, forestry, industrial plants, and public utilities. In choosing the correct grade of ear muffs, one must consider the type of equipment handled, and place of work.
In your younger years, if you did not make it a habit to protect your ears with ear muffs from damaging noise, chances are you have some degree of hearing loss – and hearing loss is not always irreversible.
We recommend you use ear muffs to protect your ears every time you use noisy machinery, even for short periods. If you are exposed to industrial noise, always wear ear muffs, as long-term exposure to noise in the workplace will result in hearing damage.
Children and teenagers must understand that hearing loss is progressive and permanent, so start thinking about protecting your hearing now rather than later to eliminate the future need for hearing aids.
Noise Reduction Ratings in New Zealand
Noise Reduction Rating (NRR) is the decibel noise reduction rating of protective products. The Australia and New Zealand standards for hearing protector ratings generally accepts that rated hearing protection is required when exposure to noise levels of 80 - 90 decibels is sustained over a period of up to eight hours.
Sustained levels of noise over 90 decibels is considered dangerous by most experts. Most machinery decibel levels range from 90 to 140 – including some Lawnmowers, Chainsaws, Brushcutters, Leaf Blowers, Airplane engines, Firearms, some Power Tools, Tractors, Motorcycles, Fireworks and Industrial Machines.
The protection NRR rating number is used to reduce noise levels to 80 decibels. For example: a noise of 110 decibels need a tested rating reduction of 30 (NRR30).
Faint Noise (protection not required)
• 20 decibels – very quiet whispering
• 25 decibels – refrigerator operating
• 30 decibels – light rain on a window, a quiet library
Moderate Noise (some form of protection should be considered for sustained periods)
• 50 decibels – moderate rainfall
• 40 decibels – quiet room with ambient noise
• 55 decibels – air conditioning unit running in a room
Loud/Very Loud Noise (ear protection should be worn for sustained periods)
• 60 decibels – conversation, microwave buzzer
• 70 decibels – vacuum cleaner
• 80 decibels – alarm clock
Extremely Loud Noise (ear protection should be worn at all times when close to the noise generator)
• 90 decibels – lawnmower, heavy traffic, power tools
• 100 decibels – chainsaw, snowmobile
• 110 decibels – industrial machines, garbage disposal
Painful Noise (combined high rating noise protection ie. plugs and ear muffs together)
• 120 decibels – jet plane engine taking off, car stereo
• 130 decibels – jackhammer
• 150 decibels – rock concert
If using non-grade tested hearing protection – anything used to protect your hearing, including placing your fingers into the ear, is better than nothing. However to be safe, commercially purchased protection should have a rating. Without this rating the protection may be misplaced.
If using basic tested hearing protection and ear plugs with a NRR28-32 rating. This kind of ear plug protection is often worn by industrial workers who work within hearing distance of loud machinery for long periods. They are a cheap, simple and effective device.