Ear plug Hearing protection

There are mainly three types of earplugs for hearing protection:

• Foam earplugs, mainly made of memory foam, which are compressed and put into the ear canal, where they expand to plug it.
• Silicone earplugs, which are rolled into a ball and carefully molded to fit over the external portion of the ear canal, providing a snug custom fit for the wearer.
• Flanged earplugs, including most types of musicians' or 'Hi-Fi' earplugs, as well as custom molds once they are molded.

NIOSH Mining Safety and Health Research recommends using the roll, pull, and hold method when using memory foam earplugs. The process involves the user rolling the earplug into a thin rod, pulling back on the ear, and holding the earplug deep in the canal with the finger.To get a complete seal, the user must wait about 20 seconds for the earplug to expand inside the canal.

Furthermore, they may be either disposable or nondisposable, with foam and silicone ones generally being disposable or for use a relatively limited number of times, while solid ones generally may be regarded as nondisposable. A variation of the traditional foam earplug is the no-roll foam earplug that uses a built-in central stem to push the foam plugs into the ears. These earplugs achieve a seal due to their tapered shape, rather than expansion after being rolled.

Ear plugs are especially useful to people exposed to excessively noisy devices or environments (80 dB or more).

Level of noise in dB(A)	Maximum daily exposure time
85	8 Hours
91	2 Hours
97	30 Minutes
103	7 Minutes