Posted on 03/10/2023 7:44:00 AM PST by LouAvul
It's a rather controversial topic among shooters as there isn't much consensus on how to do it.
There's a formula for constant noise, like one would experience while operating a bulldozer 8 hours a day, etc.
That formula, IIRC, is NRR (the noise reduction of muffs, for example) minus 7. That result divided by 2.
But that formula doesn't apply to short duration, instantaneous noise as in a gun shot.
If the shooter is wearing electronic muffs with the NRR of 30dB, and he's shooting a firearm that produces 175dB, then the dB noise reaching his ears is 145dB? Or is there a formula that changes that final number?
I know the shooter can add 5 to the NRR with properly fitted ear plugs. That would make the NRR of 30dB, 35dB.
Unless, again, the NRR numbers advertised are not really the final NRR numbers.
Thanks for any help in this.
Unfortunately the only shooting I’ve done in recent years has been in indoor ranges where I have to wear foam plugs and ear muffs..it’s still uncomfortably loud tho.
I believe that a significant risk to hearing comes through the skeletal structure if one shoulders a gun. Ear protection does not help with this.
But I want to start hunting again and I need to be able to hear ambient noise. Deer walking through leaves, etc.
Assuming the legend is accurate, 140dB and above instant/short duration noise at the ears produces damage, that's my concern.
A 30-06 rifle with 24 inch barrel produces 158.5dB of noise. My Howard Leight Impact Bolt electronic muffs has a NRR of 22. That means I'm exposed to 136.5dB which is technically in the safe range.
Unless, there is some other correction in formula for short duration noise. Hence, this thread.
You do realize you're not getting 53dB reduction? You take the higher of the two (30dB) and then add 5. You're getting 35dB NRR.
Nothing silly about that.
When I was on the 155s in the army I used the filters from my Marlboros for earplugs, it seemed to help.
How does NRR change decibels of exposure?
When hearing protection is worn, your level of exposure to noise is based on the NRR rating of the protection device being used. Keep in mind, however, that while the NRR is measured in decibels, the hearing protector being used does not reduce the surrounding decibel level by the exact number of decibels associated with that protector’s NRR. For example, if you are at a rock concert where the level of noise exposure is 100 dB and you are wearing earplugs with an NRR 33dB, your level of exposure would not be reduced to 67 dB. Instead, to determine the actual amount of decibel deduction applied (when decibels are measured dBA which is the most common), you take the NRR number (in dB), subtract seven, and then divide by two.
Given the previous example, your noise reduction equation would look like the following: (33-7)/2 = 13. This means that if you are at a rock concert with a level of noise exposure at 100 dB and you are wearing a hearing protector with an NRR 33 dB, your new level of noise exposure is 87 dB. If you are wearing a product with an NRR of 27 it would deduct 10 decibels (27-7/2=10).
How does wearing dual hearing protectors change NRR?
When hearing protectors are worn in combination (i.e. earplugs AND earmuffs), rather than adding the two NRR numbers together, you simply add five more decibels of protection to the device with the higher NRR. For example, Earplugs at NRR 29 with Earmuffs at NRR 27 would provide a Noise Reduction Rating of approximately 34 decibels.
Look up “ANSI standards for hearing protection”. You can find how devices are rated and what is required.
Also, 3M lost a recent lawsuit on their hearing protection used by members of the US military, and the documents you can find that were used in that suit can be found pretty easily, and are interesting. I did this a while back and the whole field struck me as unscientific. A lot of the regs were developed for chronic noise such as factory work, and are not well adapted for protecting from gunfire noise.
A lot of the regs were developed for chronic noise such as factory work, and are not well adapted for protecting from gunfire noise.
Yes. Hence, this thread.
“Sometimes I wear ear plugs AND ear muffs. It sounds silly to some people but I like being able to hear.”
We often do the same thing. It depends on which gun we are using for target practice. You need something a lot more for some firearms than you do others. But no matter what, if hubby can hear me yelling even with his ear protection in place, then he needs better quality protection.
I use those too. I can hear a mouse fart a mile away as well lol.
I did not know that. That’s actually pretty interesting.
I wear Walker non electronic muffs and they work great. I have occasionally used foam plugs with the muffs at the indoor gun range but not at our rural property which is where we usually shoot.
I didn’t realize it was that limited an extra protection, but I can say it works great, for several reasons.
1) If I have to take off my ear muffs, I’m still protected.
2) When both are on, I hear people talking, along with other sounds, even better, because the total noise reduction for shots is great, while I’m hearing everything else, because I have the volume up on the internal ear muff speakers enough to get the sounds I do want through my ear plugs.
It’s a win-win. I can’t say I’m hearing whispers the best, but for everything else, I, and my wife, are fully covered.
“It depends on which gun we are using for target practice.”
I agree. I won’t fire my husband’s .50 rifle because it’s like getting beat up and it is way too loud. I have a few .308 rifles and using plugs and muffs is enough to keep out the noise. I have a suppressor for my AR-10 but my precision rifles are not suppressed because it affects their range and accuracy.
Yes. As I stated earlier, that’s my gear for target shooting. But for hunting, I need to hear ambient noises. Game animals walking, etc.
I’ve done the same since I was 9 or 10 yrs old, even when playing drums...I still have excellent hearing at 50
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