By now, you’re probably asking, “Why not just use NRR 33 hearing protection all the time?”
That’s an excellent question! There are three primary reasons NRR 33 hearing protection might not be ideal for you, at least not all the time: (1) Cost, (2) Cumbersomeness/Weight, and (3) Isolation.
(1) Cost
In general, the higher the NRR, the more a hearing protection device tends to cost. This is especially true in the case of earmuffs. If a $10 NRR 19 earmuff will suffice for your needs, why buy a $35 NRR 33 Ultra Earmuff? Earmuffs do tend to get more expensive as they get more effective.
As far as earplugs go, disposable foam earplugs at the highest rating of NRR 33 are, interestingly, usually not more expensive than lower rated foam earplugs. However, those NRR 33 earplugs can sometimes be more difficult to use properly, because to get the full rated effectiveness, you really have to insert those ear plugs deeply into your ears.
Finally, when considering cost, it’s good to remember that there is usually a pretty big price difference between a pair of earplugs and a pair of earmuffs. Of course, aside from basic NRR, earplugs and earmuffs offer very different benefits. Electronic earmuffs in particular can provide many advanced hunting features -- game sound amplification, speech enhancement for safety, etc. -- that earplugs cannot, but their cost reflects those benefits. Earplugs are a lot less expensive, but tend to offer significantly fewer helpful benefits. This is generally true regardless of NRR.
(2) Cumbersomeness/Weight
This is an important consideration when it comes to earmuffs, which get their effectiveness from having a bunch of foam inside a cup which fits over the ear. The higher NRR earmuffs will weigh you down a lot more than will lower rated earmuffs. More protection usually means more weight and/or a bulkier build. That means that lighter weight earmuffs with a sleeker profile might be a more attractive solution for you, despite the loss in NRR.
Of course, concerns about cumbersomeness and weight only really apply to earmuffs; ear plugs aren’t going to be particularly cumbersome or heavy, regardless of their NRR!
Lastly -- if a low-profile fit is important to you, but you also need game sound amplification or other popular hearing enhancement benefits for hunting, a hunters’ hearing aid might be the perfect solution for you. Hunters’ hearing aids fit inside the ear canal, similar to earplugs, so they are light weight and not cumbersome at all -- but they’re also battery operated, and can provide some of the same hunting/shooting benefits as a good electronic hunters’ earmuff.
(3) Isolation
In many shooting situations, you cannot afford to be isolated. You need to be able to hear what is going on around you for safety reasons most of the time, and this is especially true when you’re holding a firearm! For example, while you’re hunting, if you can’t hear quiet game sound, you might miss the shot of the season -- or while you’re shooting at a controlled range, you absolutely must be able to hear the commands of the range officer for proper safety. In these situations, you have to balance your need for hearing protection against your need to be able to hear sounds around you. When you’re in a situation where being able to hear what’s going on around you is just as important as protecting your ears, electronic hearing protectors offer the best alternative.
What About MORE than 33 NRR?
By this point, if you’ve decided that you do indeed need the maximum protection available, you may very well be wondering, “Why not wear an NRR 33 ear plug under an NRR 33 earmuff, for a total NRR of 66?!”
That would be simple enough -- but by now, you know it isn’t going to work that way… right?
The fact is, nothing about sound is simple. Sound is measured in dB, which is an exponential scale. That means a change in the number of dB initially results in a big change in the amount of noise, but as you keep going, the effects diminish. So, an increase of 10 dB in NRR (moving from 0 to 10 NRR) will reduce the sound you hear by about half, but the next 10 dB (moving from 10 to 20 NRR) will only reduce the sound you hear by one fourth -- and the next 10 dB increment will only reduce it by another 1/8th, and so on. So by the time you get to 30, the effect of any further increases in dB is almost imperceptible.
To test this, the smart guys at Howard Leight ran some experiments to see what the effect of using earplugs under earmuffs would be. They came to the conclusion that you can get about 6 dB of extra noise protection by using both earplugs and earmuffs. The 6 dB of extra protection was pretty well constant, regardless of what the noise reduction ratings of the plugs and the earmuffs were: when added together, the highest rated of the two hearing protectors would be improved by about 6 dB.
So knowing that the improvement in NRR for using a dual-protection system is not very impressive, why would we want to wear earplugs under earmuffs? Well, wearing both types of hearing protection could be highly beneficial if neither your earplugs nor your earmuffs are NRR 33 hearing protectors. But what if your earplugs and earmuffs are 33 NRR? In that case, there should technically be no benefit at all; as we covered in an earlier article, an NRR of 33 is the maximum possible, because at that high a NRR, all sound is being prevented from entering the ear canal. So why would a dual-protection system matter at that point…?
This time, the answer is simple: human error. NRR 33 earplugs tend to be fairly sturdy, so getting them inserted properly can be a challenge. But if earplugs are not inserted deeply and worn properly, they cannot provide their maximum noise reduction rating. Similarly, if your earmuffs do not fit snugly against your head, all the way around each ear, they cannot provide the acoustic seal they need to give you their rated noise protection. So when nothing else matters but keeping the sound out and keeping your ears safe, wearing some NRR 33 earplugs under a pair of NRR 33 earmuffs may very well be your best bet: that extra 6 dB of noise reduction could make up for a flaw in how your hearing protectors are being worn.
Still, as we have discussed, NRR 33 hearing protection is not always the best choice for your unique hearing protection needs. As you have probably gathered by now, there is a lot more to choosing the right hunting & shooting hearing protection than getting that maximum 33 NRR!
Long story short: if you’ll only be doing a little light shooting with a (relatively) quiet gun, the less expensive, light weight solution makes a lot more sense. On the other hand, if you know you’ll be firing off a lot of rounds, or your firearm is particularly loud, investing in a higher-quality hearing protector will definitely pay off big in the long run.
Stay tuned for even MORE hunting season hearing knowledge -- and as always, if you need help finding the perfect hunting/shooting protection for your unique ears, we're here for you: [email protected]
Until next time, be safe and do the right thing.
--Tom "Dr. Earplug" Bergman
