Ear plugs and hearing protection devices such as ear plugs and ear muffs decrease the intensity of sound that reaches the eardrum as well as keeps away dust or particulates. Ear plugs and ear muffs vary in NRR db and come from different manufacturers such as E.A.R. Ultrafit, Moldex Jazz Band, Howard Leight Max-Lite, Bilsom Viking and North.
The effectiveness of ear plugs is reduced greatly if the hearing protectors do not fit properly or if they are worn only part time during periods of noise exposure.
Manufacturers generally provide information about the noise reducing capability of a hearing protection as an NRR (noise reduction rating) number. The higher the NRR number the better the attenuation and noise reductions.
The human aspects of hearing protection are particularly important since the only useful kind of protection is the protection that is actually worn. There are three types of earplugs for hearing protection. Foam or memory foam is the widely used by industrial workers. Earplugs made of memory foam are compressed and placed in the ear canal where the earplug expands and comforms to the ear canal opening.
