Hearing protection vs. hearing damage

[4INCHSMITH]

Wow, I always thought my 30-30 was louder than my .357. Useful info, thank you, I think I'm going to get some muffs to go with my plugs now.

[Bud Helms]

BUMP

[GlockJockey]

Glad to see this one re-emerging again, it's a great topic to which we should all pay more attention.

I've been diagnosed with Tinnitus, the constant ringing in the ears (will somebody get that 'phone!) but a while ago I sat down with a gentleman who has a doctorate in acoustical engineering here Down Under, and learned something interesting about electronic 'muffs.

Short version - don't wear them on an indoor range.

Why? The way this gent explained it to me - and I gotta say that I lack a background in maths and physics that would explain it - is that with regular earmuffs, they've got lots of padding / insulation in them to help reduce sound. With the electronic ones, you take a lot of that insulation out, and replace it with batteries, speakers, microphones, wires....all of which conduct sound to some degree.

On an outdoor range, it's not as noticeable - the sound has plenty of space to escape to; but on an indoor range, the reverberations may exceed the parameters of what the electronics can do.

Thoughts people??

[JohnKSa]

He's right in that the best non-electronic muffs typically have better NRR ratings than the best electronic muffs.

The NRR rating tells the story, there's nothing hidden in terms of how well a given set of muffs (electronic or passive) reduces the noise exposure to the ear.

Some folks will double up on hearing protection (muffs & plugs) when shooting indoors or when shooting firearms with muzzle brakes/compensators. If you're using electronic muffs, you can turn up the volume which will help you hear a bit better than if you are using plugs alone when the sound is not dangerously loud. Then, when the electronics cut off in response to a loud noise you get the benefit of plugs AND muffs. Although you can't simply add the NRR ratings of the plugs & the muffs to get the actual NRR, the combination is better than you could get with any muffs or any plugs used by themselves.

[GlockJockey]

That comment about doubling up is pretty much spot on from what I've been told. All of our instructors here are required to do this, but of course there's always a few who are too tough to do that.....

I was interested to learn from the gent that the wearing of a ballistic helmet makes very little difference to the level of noise reaching the ear. 3 dB or 4 dB at best, even with plugs. It comes back to the induction of the sound through body cavities again.

[Stevie-Ray]

If you're using electronic muffs, you can turn up the volume which will help you hear a bit better than if you are using plugs alone when the sound is not dangerously loud. Then, when the electronics cut off in response to a loud noise you get the benefit of plugs AND muffs.

Yessir. I've talked to people that use them in the indoor ranges. The idea is to use the best plug for you, as we all know that we prefer different plugs. Then the E-muffs will amplify the talking that you may want to hear and shut off the high db impulse noises like gunshots. Seems to work for the ones I talk to. I personally want mine for in the house when I want to hear a pin drop, but don't want to be deafened by the possible report of my own weapon. Whether I try them in the indoor range or not is still up in the air. After all, I don't talk to too many people there.

[Latex Ducky]

What happens when your hearing goes away and comes back?

I was shooting a .30-06 rifle a while ago and the recoil of the gun pushed my ear muff off and I couldn't hear for awhile but it seems to have returned to normal

[Bud Helms]

It may have returned, but some irreparable damage has more than likely occurred.

I accidentally left my earmuffs off once while firing a .357 Max rifle out of a pickup truck bed with an aluminum camper top on it. That hurt.

[CraigC]

Good idea to bump this one, you can NEVER stress enough the importance of hearing protection. I'm 35yrs old and already have permanent hearing damage. I can't sleep at night unless there is some ambient noise to drown out the tinnitus. While I've always used protection at the range, I did a lot of small game hunting and shotgunning in my younger years without protection and now I'm paying for it.

For anyone reading this thread that believes that you don't need hearing protection while shooting rimfires, YOU ARE WRONG! Especially with the rimfire magnums and .22LR pistols. Unless you're shooting CB's out of a long barrel.....

ALWAYS USE HEARING PROTECTION!!!!!!!!!

[FireForged]

Just how does 170 db sound reduced to 140 by a barrier know to reduce by only another 3 or 5 db when passing through the next 30 db barrier versus 140 db sound that hits only one 30 db barrier and knows to reduce to 110 db.

This is exactly what my thoughts are... I have never had anyone explain this (only 3db increase with dual barrier)

what happens when your hearing goes away and comes back

I beleive it is called a temporary threshold shift. I am not a Dr so you may want to research TTS and see if that is what you are talking about.

[WW2]

http://www.audiologyonline.com/Artic...article_id=296

[JohnKSa]

Great article. Most people don't ever even consider bone conduction--one reason why muffs can be a better choice than plugs since they cover more of the bony area around the ears.

[Don P]

I have never had anyone explain this (only 3db increase with dual barrier

)
I posted the info here awhile back. Universitys did the research. Using ear muffs that provide 30-31 db protection along with ear canal plugs will give you between 35-37 db of protection. I'll look back and see if I can find the post with the info on it.

[Bud Helms]

Let's "stick" this one again for a while.

[Don P]

Here are the web sites I spoke of. Double up when you can.
http://www.e-a-r.com/hearingconservation/
and the above use the F&Q for lots more info
http://www.e-a-r.com/pdf/hearingcons/FAQdualHPD.pdf

[GlockJockey]

I've gotta say that it's been great to read the well informed responses to this thread and see the debate, particularly on a topic that is so important to us all.

[cnimrod]

Glenjokey posted (someday I'll figure how to capture a quote):

"I've heard (no pun intended) that regardless of a combination of ear muffs and plugs, you get a maximum sound reduction of between 35 dB to 40 dB, notwithstanding numbers already mentioned. The rest comes from something called Induction. This refers to the sound that enters through the body cavities. THrough the skull itself, through the hollow parts of the throat (even when your mouth is closed), through reverberation from the chest cavity.....you get the idea."


I've read to the contrary and I'll try to find the source, but if you open your mouth when shooting it actually reduces the sound impact on your ears. I do it, while still using earplugs, and it does feels more comfortable. I would guess in this case it actually allows the 'inducted' sound out of your skull vs in. try it, what have you got to lose.

blindness separates us from the world, deafness separates us from people.

[Tucker 1371]

Never knew that, I think I kind of subconsciously let my mouth open when I'm shooting, I guess I feel a little more relaxed that way.

I always just use plugs and I think I do fine, most muffs screw up my cheek weld. I used to shoot without them until my 20ga made my ears ring for about an hour straight . Wouldn't even think about shooting my Mosin without them, I sometimes shoot my 5.45 AK without them but never more than 30-120 rds. I don't think it hurts too much, definitely not as bad as going for a 2mi run listening to Metallica on my iPod , it just doesn't have the same effect when you play it quiet.

[JohnKSa]

I've heard the "open your mouth" advice given in relation to being around very loud noises/explosions without hearing protection.

The rationale I heard was that your open mouth allows some of the blast pressure inside your mouth and into your ears through the tubes that empty from your ears into your throat. The idea is that the pressure coming through the tubes equalizes the pressure in your ears and may help prevent your eardrums from rupturing from the blast.

If you're using hearing protection I think you're better off leaving your mouth closed.

[ka041a]

amen to that gentlemen,
i now have to live with constant ringing in my ears that could have been prevented with a set of ear plugs that cost less than one single round of ammo. live and don't learn, that's me! also do not ever discharge a firearm without eye protection, because the tiniest speck of debris going the wrong direction could cause a horrible tragedy. thank you

[Stevie-Ray]

If you're using hearing protection I think you're better off leaving your mouth closed.

You are correct, John. At Fort Michilimackinac, when they demonstrate a cannon, they tell you, "Put your hands over your ears or open your mouth, but don't do both."

[DogoDon]

I'm new here and this is my first post, so be nice, guys, and don't jump down my throat if I say something dumb.

I was reading this thread with great interest, as I certainly want to protect my hearing. I'm basically a novice shooter (at 50 years of age!). I read the debate about whether wearing both ear muffs and ear plugs provides an additive decibel reduction or not. Somebody mentioned a rule of thumb that the overall db reduction is 5 db more than the db reduction provided by the better of the two devices. So, if the muffs give 26 db reduction and the plugs give 25 db reduction, the total reduction would be 26+5=31 db. That sounded crazy to me, so I did a little nosing around and found somebody who has studied it and published a paper about it. I don't have the full paper, but here's the abstract:

Author: Alberto Behara

Ontario Hydro, 757 McKay Road, Pickering, Ontario, Canada L1W 3C8

Abstract
It is generally accepted that the total attenuation, when wearing a muff on top of a plug, is 5 dB higher than the highest of the individual attenuations of each of the protectors. A recent paper by A. Damongeoet et al., Appl. Acoust., 28 (1989) 169-75, lists results from 32 laboratory measurements of attenuations resulting from wearing simultaneously a muff and a plug, performed at five different laboratories. The resulting mean attenuation of the database was 7 dB. However, individual attenuation values ranged from 0·6 to 12 dB, defying the validity of the 5 dB rule. In this paper several attempts for a general rule for predicting the combined attenuation have been postulated, none with success. The conclusion is that a combination of protectors should not be worn unless the resulting attenuation is known.

So it seems that it is not a simple matter to determine the overall sound reduction of both muffs and plugs. But as far as I'm concerned, using both has to be better than using only one.

[adively]

NIOSH - Information for Hunters and Shooters
http://www2a.cdc.gov/hp-devices/huntershooters.html

In most cases, the sound level from firing a weapon is sufficient to require the use of hearing protection, even if the weapon is fired only one time. Recent NIOSH studies of sound levels from weapons fires have shown that they may range from a low of 144 dB SPL for small caliber weapons such as a 0.22 caliber rifle to as high as a 172 dB SPL for a 0.357 caliber revolver.

Consequently, NIOSH recommends that hunters and shooters use double hearing protection each and every time a weapon is fired. Double protection involves wearing both earplugs and earmuffs. The best combination is a deeply inserted foam earplug and a well-seated earmuff.

NIOSH examined the performance of several types of hearing protectors with a variety of weapons. Earplugs were able to reduce the peak sound pressure level by 10 to 30 decibels and earmuffs yielded 20 to 38 decibels of peak reduction. Active level-dependent earmuffs were found to react sufficiently fast to provide the same protection level as when they were turned off [Murphy and Little (2002) J. Acoust. Soc. Am. 111:2336; Franks and Murphy, (2002). J. Acoust. Soc. Am. 112:2294]. The effect of volume gain setting was minimal for active level-dependent devices (see Figure 1). Each protector was tested with the volume set for unity gain, maximum gain or turned off. At unity gain the sound under the protector is as loud as when no protector is worn. The peak reduction was mostly unaffected by the change in the volume setting.

The formula for determining the maximum number of shots is:

10(140-pldB)/10

where pldB is the peak level of the sound in the ear canal under the earmuff and earplug. NIOSH recommends that peak exposures be limited to one event not exceeding a peak level of 140 dB SPL. That is, exposure to one event of 140 dB SPL would constitute 100% of a persons’s noise burden.

As shown in Figure 2, the amount of reduction for 12-gauge shotgun using the David Clark Model 27 earmuff is 31 dB, reducing the peak level from 161(red line) to 130 dB SPL( blue line). So, with the earmuff alone, the number of shots recommended by NIOSH would be five per 24-hour period. The addition of a deeply inserted foam earplug reduces another 21 dB, increasing the allowed number of shots to more than 1200 per 24-hour period. A smaller caliber weapon with a lower peak level, such as 0.22 caliber rifles with peak levels of 144 dB SPL, could be fired as many as 63000 rounds per 24-hour period if the shooter were to wear an active level-dependent earmuff along with a deeply inserted foam earplug. The combination of an earmuff and a deeply-inserted foam earplug can provide as much as 50 dB of peak reduction, which is adequate in most cases.

Double hearing protection can severely compromise the ability to communicate when both devices are passive, linear protectors. The use of an active level-dependent earmuff with a deeply-inserted foam earplug can compensate for the loss of communication ability when double protected. In some cases, the earmuff may provide sufficient gain to counter the attenuation of the earplug.

For shooters, a key indication that whatever protection is being used is inadequate is ringing of the ears or a feeling of fullness in the ears after an episode of shooting.

There are also active level-dependent hearing protectors that are built into pre-molded earplugs and custom earplugs as well on the market. There are no data on their effectiveness. At present, there are no data on the use of an active level-dependent earplug in combination with a passive earmuff. Given the attenuation chain, it is doubtful that the pairing would be as effective as the active level-dependent earmuff with foam earplug.

[cnimrod]

don't know anyone who wears ear protection and personally shooting a 12 ga and .308 over the last 30 years has never bothered me in a hunting situation. no doubt focussing on the game changes ones perception of the shot. Yeah i'm sure the damage is still done but I'm as likely to blame 25 years of marriage than I am my guns Anyone use those "Action Ears"?

[ZeSpectre]

but when hunting I don't know anyone who wears ear protection

Boy I sure do! Some of my friends consider me excessively careful with my hearing and have teased me a lot about it (I wear foam plugs in noisy bars and especially at concerts) .

Yet at 41 I can still hear most of the "mosquito" ringtones and that sort of thing so I think I got it right in the past.