The Noise Reduction Rating (NRR) is a standard rating for the noise reduction of any ear plug. The higher the better. The highest rating you can buy for an ear plug is NRR 33. You can achieve higher ratings by stacking. That is by using ear muffs and ear plugs at the same time. An NRR of 34 can be achieved by wearing NRR 33 ear plugs and NRR 20 ear muffs. Ear muffs come in ratings from NRR 20 to NRR 31. You can get an NRR of 36 by wearing NRR 33 ear plugs and NRR 31 ear muffs at the same time.
Hearing protection ear plugs include disposable foam plugs, moldable silicone plugs, moldable wax plugs, pre-molded silicone and rubber plugs.
Poly Urethane Foam Ear Plugs (Disposable)
Poly Urethane Foam Ear Plugs are the softest foam plugs available. They are designed to be rolled into a thin cylinder, then inserted deeply into the ear where they expand to fit. Some are available with a cord to hang around your neck. That can get in the way though, so try them out before you buy a hundred.
Some brands and their NRR rating are listed below:
MAX NRR 33
LaserLite NRR 32
MaxLite NRR 30
3-M 1100 NRR 29
EarSoft Yellow Neon Blast NRR 32
Sleep/Rest EAR plugs NRR 32
PVC Foam Plugs (Disposable)
PVC foam plugs are stiffer than the urethane foam plugs and are not tapered. You need to make sure they are inserted properly to get the most benefit.
Classic NRR 29
SuperFit 33 NRR 33
Quiet! Please–Industrial NRR 29
Moldable Silicone Plugs (Reusable)
Moldable silicone plugs are soft and best suited for water protection and moderate noise protection in clean environments. This can include sleeping, studying and biking. They are sticky and form a seal against the outer surface of the ear. They are very comfortable but they can get dirty and can not be cleaned effectively.
Mack’s Pillow Soft Silicone NRR 22
Flent’s Sealrite NRR 21
Wax plugs are unique in that they contain cotton fibers which hold the wax together. Body heat will soften the wax allowing it to shape to your ear and seal without exerting any pressure. This makes them very comfortable, but they are not a good choice for hot or active environments.
Flent’s Ear Stopples NRR 25
Pre-Molded Silicone Rubber Plugs (Reusable)
Pre-molded silicone rubber plugs come in all shapes and sizes and are designed for noise, water, music, flying pressure, and shooting. You need to get a good fit, and they are best bought over the counter where you can try them out. They can be washed and reused. They may not meet the NRR ratings of the foam plugs but they can last for years. If you can find a pair that fits you well, they can be the most economical choice.
The general guideline is – Make sure that you always use some form of hearing protection when using your Stihl Chainsaw.