Ear plugs are a protective device that can either be inserted into the ear canal (as with the foam or rubber varieties) or used to create a air-tight and water-tight seal over the opening (as with the mouldable silicone varieties).plugs are good hearing protection devices that are generally used as a form of noise protection, but unlike ear muffs they won't keep your ears warm and dry. Ear plugs are small plugs that are inserted into your ear canals to filter out certain degrees of noise. They are often made of non allergenic, self adjusting foam, rubber or a similar type of squishable material. 

Excessive, constant and loud noises can destroy irreplaceable cells in the inner ear and cause hearing loss. This is why it's a good idea to protect your ears from these noises by wearing ear plugs. A normal person can suffer hearing damage when noises reach their ears at a rate of 85 to 90 decibels. 

To insert ear plugs, you basically pinch the ear plugs or squash them down to a small size and insert them into your ears. When the ear plugs are in your ears they will then expand a little for protection. Some ear plugs are individual pieces; while other models are attached together with a thin cord or a head band. Most of these types of ear plugs are worn in factories, on construction sites, and at concerts, etc. Most ear plugs are disposable models that you wear once and throw out for hygienic reasons. However, reusable and washable ear plugs are also available along with custom-made ear plugs. 

The Environmental Protection Agency states that all ear plugs have to be labeled with a Noise Reduction Rating (NRR). The number on the ear plugs indicates how many decibels the ear plugs are designed to reduce noise by. The higher the decibel number; the more noise will be filtered out. So if your ear plugs are rated NRR 34 and you wear them in an area with 100 decibels of noise you should only hear 64 decibels of noise. A good pair of ear plugs should also be moisture-resistant and comfortable. Ear plugs are also available in a variety of styles and sizes.