They are designed for convenience in work areas with varying noise levels. Communication headsets block unwanted noise while allowing the wearer to communicate with co-workers. Microphones suppress environmental noise to aid in two-way communication. Ear caps seal the opening to the ear without entering the ear canal. Similar to band-type hearing protectors, they usually come on a band that can be placed around the neck when the caps are not in use.
Ear muffs completely suppress unwanted noise by completely covering the outer ear.
Disposable ear plugs are made of formable material and are designed to be inserted into a person's ear canal, where they can expand and conform to the shape of each individual's ear. Reusable ear plugs are usually premolded and made from silicone, plastic or rubber, and are available in several different sizes. They often come in a carrying case to keep them clean when not in use. Individual copies of the guide are available without charge.