Noise and Hearing – The More We Hear Today
September 15 2004
Permanent, irreversible hearing loss, can occur daily to people who are subjected to loud noises even when they are in seemingly innocuous situations. The air bag deployment in a vehicle involved in a minor accident or passing by a car alarm when it sounds are all loud noises that occur in our daily lives. Construction workers are at risk on loud construction sites. Many airport workers are losing their hearing. Dentists and dental hygienists are at risk due to daily exposure to their dental equipment. Toys are noisy too and can be hazardous to childrens hearing – from baby rattlers and young childrens squeaky toys to older childrens cap guns. This is to name but a few of the culprits. Our world is a noisy one. We must be aware of the danger to our hearing and what we can do to prevent hearing loss.
Measuring Noise: What is too Loud?
The intensity of sound is measured in decibels (dB) in a scale that ranges from 0dB (the faintest sound the human ear can detect) to more than 180dB which is the noise at rocket launch pad. A significant cut off point occurs at 85dB (roughly the sound of a vacuum cleaner or dial tone on a telephone). Sounds of this intensity or louder are considered hazardous to hearing. The longer the ear is exposed to noise, the more damage it causes to hearing. The effect is cumulative and irreversible. Even moderate levels of noise can prove detrimental to hearing, given enough time.
Temporary or Permanent Hearing Loss
The damaging effects of noise on our hearing are not always easily apparent during the early stages of noise exposure. At first, the hearing loss may be temporary with hearing being recovered some time after the noise exposure has stopped.
Over time, repeated exposure to sounds that cause temporary hearing loss may gradually cause permanent hearing loss. A hearing loss caused by noise exposure is called a Anoise-induced hearing loss. People with noise induced hearing losses typically have reduced hearing for high pitch sounds. In general, the louder the noise and the longer you are exposed to it, the greater the amount of hearing loss.
Acoustic trauma is an immediate severe and permanent hearing loss which results from a short-duration, and very loud sound, such as the sound of gunfire. This intense sound usually exceeds the threshold of pain and can have additional devastating effects on the individual such as dizziness, nausea and tinnitus (ringing in the ears).
In over 90% of the cases of individuals who suffer from tinnitus, there is a history of noise exposure.
As we know, noise should always be reduced at its source. But while we work to change peoples minds – and our by-laws- about noise, there are some ways we can protect ourselves as we go about our everyday lives.
There are two main types of hearing protection: ear muffs and ear plugs. Ear muffs cover the entire ear and provide the maximum amount of noise attenuation. They are, however, often cumbersome and are heavy on the ears. Ear plugs are often preferable because they are cheaper, more comfortable and accessible, and are appropriate for everyday wear.
The success of any ear plug is not the brand name bought, but how they are used. The more experience you have on how to fit and use your ear plugs, the greater the protection.
- One-size-fits-all ear plugs are usually made of foam or sponge. With clean hands, roll and compress each plug between thumb and forefinger before inserting firmly, and as far as possible, into the ear canal. Give the ear plug a few seconds to expand fully inside the ear canal, to assume the shape of the ear canal itself.
- Custom molded ear plugs are made for each individual ear and are by far the most comfortable and easy to use. Musician Ear Plugs are also available which reduce harmful background noise but at the same time allow music and/or speech to be heard clearly through the noise.
Awareness of potential excessive noise circumstances is critical. We all can help in raising with others the concern of excessive noise generally, or in particular situations. The bravado of youth, and a belief that something you can’t see cant hurt you, has led to many examples of hearing loss in middle age.