Disposable ear plugs
Disposable ear plugs are made out of foam, silicone or some other soft material. After they are inserted into the ear canal they block out harmful sound. They can have a NRR of up to 33 dBA. The actual noise reduction varies greatly between people, depending on their individual ears, and how well the plug fits.
Other generic plugs are available that are made of more robust material. These plugs can be worn over and over again.
Custom fit ear plugs
Custom fit ear plugs are fitted to a persons ear for an exact fit. They are made from a silicone or acrylic material. Because they are custom made to fit a specific ear, they function consistently and have an NRR of up to 31 dBA.
Earmuffs
Earmuffs are worn over the ear, and like custom fit ear plugs function consistently. They have an NRR of up to 30 dBA, and can be worn with other ear plugs for even greater sound protection.
Hocks Noise Brakers®
The Noise Braker® comes in both a standard and custom model. The standard model (pictured here) is a generic ear plug with a Noise Braker® filter inserted. The custom model is simply a custom fit ear plug, with a Noise Braker® filter inserted. Noise Brakers® do not block sound, they let it in at a reduced volume. The amount of sound that is filtered out depends on how high the volume is. As noise levels increase, so does the amount of hearing protection! (See how the Noise Braker® works.)
The Noise Braker® has an NRR of 19 dBA. The actual amount of noise reduction depends on fit (in the case of Noise Braker® Standards), volume (The louder the volume, the more noise is reduced), and pitch (lower sounds are not reduced as much as middle to high sounds). For more information see the test data.