88, страница 49
Small tips reduce foam pressure in ear
device called the ZEM you might want to try. It works a little differently. Instead of blocking the ear canal, a filter chamber contains material that directs the sound away from the ear (photo upper right).
Ear Muffs. The hearing protector I find most comfortable to wear is a muff-type unit, like those shown in the photo on the previous page. They fit over the entire outer ear to form an air seal that blocks sounds
Foam plugs need to be replaced often
from entering the ear. An adjustable band lets you customize the fit.
The only problem with muff-type protectors is if you have long hair, wear eyeglasses, or use safety glasses it may be difficult to get the ear piece to seal properly around your ear. This can cause you to lose some degree of protection.
High-tech electronic muffs are also available. You can learn more about them in the box below.
Combined Protection. When using really loud tools, like a chain saw, I like to wear both ear muffs and ear plugs. Noise produced by these tools can remain in the harmful range even with a protective device in place. Using both types in combination can reduce the sound an additional 10 to 15 decibels. This helps ensure the noise level will remain at or just below the harmful level. &
m Hearing Protectors.
Most shop noise can be reduced to a safe level by using simple protective devices.
At first glance, the hearing protector shown at right looks just like a standard ear muff. But it's what's on the inside that makes a difference in how it works.
Like a standard ear muff, the Noisebuster reduces mid and high frequency sounds, but it also features electronic noise reduction to reduce low frequency noise (typical of engines and motors) that can really be harmful and dangerous.
To do this, a microphone inside the ear cup (drawing at right) monitors the noise coming into the ear piece. Then using electronics, a "mirror" image of the low frequency noise is created. This "anti-noise" is output into each ear cup and reduces these low frequency sounds another 20dB.
Plus, it makes it easier to understand speech and warning signals — an added safety benefit
in a shop. The model shown at right also has a jack that lets you plug in a portable radio or audio player so you can listen to your favorite music at a safe level.
Technology like this isn't cheap. The Noisebuster runs around $150. Other manufacturers make units costing $300 and more. For more information about these and other devices, turn Sources on page 51.
Audio player cable and connection
These ear muff protectors use electronics to reduce harmful sounds to a safe level.