View Full Version : Suppressor and hearing protection
1_click_off
11-22-17, 08:35
Not really a fit for NFA forum as this is actually more of a question of ear safety.
I keep reading that suppressors do not make supersonic ammo ear safe.
My question is if the suppressor is advertised for a 31dB NRR (Dead Air Sandman-L) and ear plugs have a NRR of 22-32, how can the suppressor not be ear safe?
Is it the supersonic crack of the bullet that prevents the safe hearing level?
Is this just a general assumption a can will not make the report ear safe due to the smaller cans not reducing the noise as well as the behemoth Sandman-L?
SomeOtherGuy
11-22-17, 09:11
Not really a fit for NFA forum as this is actually more of a question of ear safety.
I keep reading that suppressors do not make supersonic ammo ear safe.
My question is if the suppressor is advertised for a 31dB NRR (Dead Air Sandman-L) and ear plugs have a NRR of 22-32, how can the suppressor not be ear safe?
Mostly the supersonic crack. However, there's also the issue that the volume at the muzzle can be more than 50-60db above the hearing safe threshold, depending on the cartridge and barrel length. I don't think this is common, but it could happen with a large bore, high pressure cartridge in a short barrel.
Is it the supersonic crack of the bullet that prevents the safe hearing level?
YES. The best way to experience this is in the target pits for a 600 yard competition. You will not hear the report from the muzzle, but the crack of each bullet passing above will be almost as loud. For the big ones it may seem louder! And this is when they are down to 1500-1800fps. The supersonic crack is louder still at higher velocity.
Is this just a general assumption a can will not make the report ear safe due to the smaller cans not reducing the noise as well as the behemoth Sandman-L?
No.
1_click_off
11-22-17, 09:28
Wasn’t sure where they take the sound reading from.
Wish I had a range with 600yds within even an hour drive from me.
Ok, guess I knew the answer. I was just hoping that the suppressor was more benificail for the shooter than those around the shooter. I know, I know, it all depends on the needs of the shooter.
I love my Sandman. The neighbors get agitated with more than 22fire, so the sandman allows me to cheat some on that front. It’s a shame when 25 acres gets too small!
SomeOtherGuy
11-22-17, 09:37
Wasn’t sure where they take the sound reading from.
Wish I had a range with 600yds within even an hour drive from me.
Ok, guess I knew the answer. I was just hoping that the suppressor was more benificail for the shooter than those around the shooter. * It’s a shame when 25 acres gets too small!
I think the SPL readings are taken from the position of the shooter's ear, but I'm not sure if that's consistent.
Both shooter and bystanders benefit greatly from any suppressor.
The experience of shooting at 600 yards or longer is worthwhile, find a way to do it even if it means an overnight trip. It's much different from, and to me more interesting than, shooting at 100 yards and less.
1_click_off
11-22-17, 10:07
Buddy of mine has a hunting lease about 4 hours away. I went out there to shoot my Barrett a few years ago. We got out to 660yds. Had all the elevation I could get out of my VX-III to get it doped.
It was turkey season and the club would not let us take vehicles or 4wheelers off the road to check impacts. So it was about a 1500yd treck one way to check the target because of the hills of the pipe line. The target was on hill 3.
Here we are lighting off XM33 and we can’t drive a 4wheeler to check the target!
I was shooting at a letter sized piece of white paper. I nicked it on the right, nicked it on the top, and pulled it just left once I had the scope dialed in.
Never realized how much has to come together to make those long shots. Breathing, shooting between heartbeats, shooting before eye strain sets in, oh yeah, and the calming back down after the 3000yd walk!!
It was a fun day, got my exercise too!
I was just hoping that the suppressor was more benificail for the shooter than those around the shooter.
That is absolutely the case in my experience. Almost all the suppressed rifles we shoot are (at best guess) hearing safe for the shooter. If I'm out front of any rifle the crack seems to be too loud to be hearing safe.
The other factor is (on auto loading guns) port "snap". I had one are I had to quit shooting suppressed because, for whatever reasons, the port snap was so loud, it hurt my right ear when firing it.
My question is if the suppressor is advertised for a 31dB NRR (Dead Air Sandman-L) and ear plugs have a NRR of 22-32, how can the suppressor not be ear safe?
The ear plugs are not hearing safe either, for many gun reports.
1_click_off
11-22-17, 11:50
The ear plugs are not hearing safe either, for many gun reports.
Whaaaaattt?????
Whaaaaattt?????
I guess you found out the old fashioned way. :-)
I still use hearing protection when shooting suppressed. It's still loud even with a can on the end. Some are louder than others and I will agree that it is bearable without but for me I don't want any more hearing damage later in life than I already have from working in a power plant...
1_click_off
11-22-17, 12:11
I guess you found out the old fashioned way. :-)
Yeah, my dad did me no favors taking me out shooting as a kid. 357 magnum, 44magnum, single six (don’t laugh, they are loud!) all without protection. He broke out the muffs and plugs later in life, but the damage was already done. I can remember not being able to hear until mid afternoon the following day.
My kids have never been exposed to an unsuppressed round. They shoot the standard velocity CCI suppressed, so we go muff free for that. Anything more and it is suppressed and muffs (for them and me).
Doc Safari
11-22-17, 12:41
The ear plugs are not hearing safe either, for many gun reports.
Could you be more specific? I've used earplugs for years with no issues except having to use an ear wax removal kit after most range sessions.
Could you be more specific? I've used earplugs for years with no issues except having to use an ear wax removal kit after most range sessions.
Muzzle Blast from a given 22LR Rifle is 140dB At the ear. You are wearing muffs with NRR of 22dB. 140-22 = 118dB at your ear. Hearing safe.
Muzzle Blast from a given 7.62 Rifle is 167dB At the ear. You are wearing muffs with NRR of 22dB. 167-22 = 145dB at your ear. Not Hearing safe.
Doc Safari
11-22-17, 12:52
Muzzle Blast from a given 22LR Rifle is 140dB At the ear. You are wearing muffs with NRR of 22dB. 140-22 = 118dB at your ear. Hearing safe.
Muzzle Blast from a given 7.62 Rifle is 167dB At the ear. You are wearing muffs with NRR of 22dB. 167-22 = 145dB at your ear. Not Hearing safe.
So, most places selling GI earplugs on the net quote 25 dB noise reduction. That means if you shoot an AR10 you better have more.
I've started using the Otis Ear Shield at 31 dB with my Glock and AR. It seems to reduce the blast adequately.
For 22LR they reduce the blast to 109. GTG.
For 7.62, that would be 136. Not so good.
What are the dB values for a 16" carbine and a 9mm Glock at the muzzle?
So, most places selling GI earplugs on the net quote 25 dB noise reduction. That means if you shoot an AR10 you better have more.
I've started using the Otis Ear Shield at 31 dB with my Glock and AR. It seems to reduce the blast adequately.
For 22LR they reduce the blast to 109. GTG.
For 7.62, that would be 136. Not so good.
What are the dB values for a 16" carbine and a 9mm Glock at the muzzle?
Most places say an 5.56 is around 150.
109db is not necessarily good to go, at that level you can begin to suffer hearing loss with less than two minutes exposure. Depends on your dosage each time in order to forsee cumulative results.
I don't shoot anything, suppressed or unsuppressed, without double protection - plugs and muffs.
So, most places selling GI earplugs on the net quote 25 dB noise reduction. That means if you shoot an AR10 you better have more.
I've started using the Otis Ear Shield at 31 dB with my Glock and AR. It seems to reduce the blast adequately.
For 22LR they reduce the blast to 109. GTG.
For 7.62, that would be 136. Not so good.
What are the dB values for a 16" carbine and a 9mm Glock at the muzzle?
167 for 556 - https://www.youtube.com/watch?v=IaaIFBBB9-Q
161 for Glock 17 - https://www.full30.com/video/f4bdb7218a1de4823bb027ea271052cb
Doc Safari
11-22-17, 15:55
To get to the crux of the matter it's difficult to shoot AR's with full-blown muffs because they can interfere with your cheek weld (yes, I've tried many).
So the solution would seem to be: ear plugs AND the Otis Ear Shield.
(And I'm assuming no suppressor use since a lot of people don't have that option).
AND....to muddy the waters: is it possible to sustain hearing damage without "perceived" loudness, i.e., if you can note that the sound is no longer uncomfortable or ear-splitting with protection--is that NOT a reliable indicator of how effective the ear protection is?
1_click_off
11-22-17, 15:55
Most places say an 5.56 is around 150.
109db is not necessarily good to go, at that level you can begin to suffer hearing loss with less than two minutes exposure. Depends on your dosage each time in order to forsee cumulative results.
I don't shoot anything, suppressed or unsuppressed, without double protection - plugs and muffs.
dB safe levels have more to it than just a peak dB. There is a duration of time and cycle per second. So a single pulse of 109 might be the equivalent to 90 constant. I have a good friend that has a brother that is an Otolaryngologist. I will see if he can give some insight on this.
I double up at all times. Ear plugs then electronic muffs turned all the way up. The amplified muffs make it so I can hear an instructor even with good quality ear plugs in.
With a reduction of 20-25db, most suppressors are not hearing safe enough for me. I'd still be wearing plugs or headphones at the range.
Doc Safari
11-22-17, 15:58
Another thing: raw dB numbers may not tell the tale if the majority of the "blast" is going out the muzzle away from you. In other words, if you are standing to the side while someone shoots, you may get a "louder" dose than if you are the shooter and all the sound and fury is going downrange.
Or so it seems this would be the case.
Another thing: raw dB numbers may not tell the tale if the majority of the "blast" is going out the muzzle away from you. In other words, if you are standing to the side while someone shoots, you may get a "louder" dose than if you are the shooter and all the sound and fury is going downrange.
Or so it seems this would be the case.
I already eloquently made that point, old chap! :cool:
Standing down range of suppressed fire hurts my ears... but not shooting that exact same gun.
Doc Safari
11-22-17, 16:16
I already eloquently made that point, old chap! :cool:
Okay, well, kinda. I was getting more to raw dB numbers not being enough to assess danger to hearing.
Standing down range of suppressed fire hurts my ears... but not shooting that exact same gun.
Same with me unsuppressed but with hearing protection.
The worst I ever experienced was when I went to the range with my buddy and his 10.5" 5.56. I was standing approx. 2 feet behind his muzzle and about 3 feet to the side of him at my own shooting bench. He started firing un-suppressed, with a muzzle brake, without warning. Even though I was wearing my Howard Leight Impact Sports, my ears hurt like hell.
I'm already hearing impaired, and yet the noise was so piercing I walked behind the firing line and sat down until he was finished. From now on, if I expect to be around a really loud gun, I'm wearing plugs and muffs.
Suppressed, the ear muffs may have been enough, but with my ears ringing the rest of the session I was't about to find out.
Rayrevolver
11-22-17, 19:13
Gents, I don't think we are doing the math correctly. If you look at something like the Surefire EP10 you would think they are only good for 30db. But read the detailed literature and its actually not the case. It says on Page 3 that with impulse noise at 165db, the attenuation is 45.9db.
So 165 - 45.9 = 119.1db for your average centerfire cartridge.
The number that we always get is some sort of average across the frequency range, as shown on the top of Page 3.
http://www.surefire.com/media/wysiwyg/main_site_pdfs/EP7_Sonic_Defenders_Ultra.pdf
Hopefully someone with a background in this stuff can chime in.
For every 3 db's rise in the sound level your safe exposure time is halved.
119db has a safe exposure level of less than 15 seconds. The doesn't mean that with 30 exposures of 1/2 second you will have hearing loss, but your exposure is somewhat cumulative per range session.
The reality is that regardless of how you protect yourself, if you shoot enough you will have hearing loss.
Ask the guy with two hearing aides who religiously plugged and muffed over his career.
SomeOtherGuy
11-22-17, 20:04
Gents, I don't think we are doing the math correctly. If you look at something like the Surefire EP10 you would think they are only good for 30db. But read the detailed literature and its actually not the case. It says on Page 3 that with impulse noise at 165db, the attenuation is 45.9db.
So 165 - 45.9 = 119.1db for your average centerfire cartridge.
The number that we always get is some sort of average across the frequency range, as shown on the top of Page 3.
http://www.surefire.com/media/wysiwyg/main_site_pdfs/EP7_Sonic_Defenders_Ultra.pdf
Hopefully someone with a background in this stuff can chime in.
You are doing the simple math correctly, but real-world noise attenuation doesn't follow the simple math. The main problem is that sound can reach your eardrums, and the little nerves that matter, through your skull, and your mouth and nasal passages, as well as through your ear canal. It is possible for the earplug to block tons of noise, such as the 45.9db you cite, but sound makes its way around it also. The maximum practical sound reduction is around 30-35db, no matter what combination of plugs and muffs you use. And getting to ~35db requires the best plugs (fortunately cheap foam are the best) and the best muffs.
Unless, maybe, you have some kind of astronaut helmet that tightly seals around your neck!
It is still beneficial to buy the highest NRR rating you can find, and to double up both earplugs and muffs, but it's not a full solution.
Rayrevolver
11-22-17, 20:57
I agree 100%. Muffs help attenuate the noise around your ear/head whereas plugs do not. Not much you can do for the rest of your noggin short of a helmet. All the more reason suppressors should be readily available. Tell the people!!!
For the last few years I have doubled up when going loud. I double up even with 5.56 suppressed. At home, with 22LR or 9mm suppressed, I wear muffs only. Its funny that today I almost doubled up but didn't. Shot a suppressed PCC with subs, muffs only. I am starting to think I should double up always, regardless.
My plugs are the Surefire EP7s with a 28db rating with those ports closed. I guess where I lack top level protection is with the muffs, the Impact Sports or the Peltor Sport Tacs are both NRR 22db.
EDIT: A while back I almost pulled the trigger on MSA Sordins but then saw their NRR 18/19db rating. That lead to a bunch of reading and lead to this page with some good overall info:
https://trevoronthetrigger.wordpress.com/2014/05/01/msa-sordin-supreme-performance-the-misleading-nrr18db-rating/
The other big takeaway is that these NRRs are not additive. So a NRR 22 muff and NRR 22 plugs combined DO NOT = NRR 44 across the scales.
I am still on the fence about whether I should upgrade my muffs to Sordins or some other high dollar muffs.
Muzzle Blast from a given 22LR Rifle is 140dB At the ear. You are wearing muffs with NRR of 22dB. 140-22 = 118dB at your ear. Hearing safe.
Muzzle Blast from a given 7.62 Rifle is 167dB At the ear. You are wearing muffs with NRR of 22dB. 167-22 = 145dB at your ear. Not Hearing safe.
Double protection for rifles for range time. Plugs +muffs or silencer +muffs/plugs.
Exception is hunting.
At least these are my personal guidelines.
I worked for an audiologist for a few years and he explained to me that Sound waves travel through your body, and high dB impulses at certain frequencies will damage your hearing no matter what ear protection you have. You can actually take a hearing test through your forehead. It’s best to suppress (see what I did there) the source of the noise.
This thread is kind of funny. My mom and I were just talking about my dads hearing the other day. She thinks he mostly ignores her. I assured her that that is the case sometimes. However, my dad was in Vietnam during the Tet Offensive. He shot and been shot at with just about every small arm of that era (M16, M60, M2, quad 50's, AK47, PK, RPG, mortars, hand grenades).
I told her they didn't wear hearing protection and that damaged his hearing. Plus all he's ever done is worked in loud factories and power plants after that. I don't think she bought it.
NYH1.
85dB is the general point that everyone basically considers you can be around safely for a work day. It's also the point or close to it that most movies and audio is calibrated to.
If you guys are pondering 120dB ranges and thinking you are 'safe', you probably are not. I believe most concerts, at least the outdoor ones that could disturb neighbors and such have a 110dB limit and that's very close in, not way off from the stage somewhere.
Also when you read about safe dB levels they are almost always talking about noise meaning it's a continuous broadband. I'm pretty sure percussive sounds put a whole new spin on things and not in a good way.
As to where to measure. If you want to know what it does for the shooter you measure at the shooters ear. If you wanted to measure something else you put it there but comparisons should be the same. You don;t measure one at the ear and one six feet off to the side.
If one guy measures at 120dB at 1 meter and the next guy measures at 2 meters he will get 114dB. So everyone taking measurements anywhere they want is pretty much useless.
Any prolonged exposure over maybe 83dBA is probably going to result in hearing damage.
85dB is the general point that everyone basically considers you can be around safely for a work day. It's also the point or close to it that most movies and audio is calibrated to.
If you guys are pondering 120dB ranges and thinking you are 'safe', you probably are not. I believe most concerts, at least the outdoor ones that could disturb neighbors and such have a 110dB limit and that's very close in, not way off from the stage somewhere.
Also when you read about safe dB levels they are almost always talking about noise meaning it's a continuous broadband. I'm pretty sure percussive sounds put a whole new spin on things and not in a good way.
As to where to measure. If you want to know what it does for the shooter you measure at the shooters ear. If you wanted to measure something else you put it there but comparisons should be the same. You don;t measure one at the ear and one six feet off to the side.
If one guy measures at 120dB at 1 meter and the next guy measures at 2 meters he will get 114dB. So everyone taking measurements anywhere they want is pretty much useless.
Any prolonged exposure over maybe 83dBA is probably going to result in hearing damage.
Impulse noise is allowed a higher dB than constant noise.
Averageman
11-23-17, 09:59
This thread is kind of funny. My mom and I were just talking about my dads hearing the other day. She thinks he mostly ignores her. I assured her that that is the case sometimes. However, my dad was in Vietnam during the Tet Offensive. He shot and been shot at with just about every small arm of that era (M16, M60, M2, quad 50's, AK47, PK, RPG, mortars, hand grenades).
I told her they didn't wear hearing protection and that damaged his hearing. Plus all he's ever done is worked in loud factories and power plants after that. I don't think she bought it.
NYH1.
I was a Tanker for 21 years, I often verified boresights on those cannons while others 50 or so feet away from me fired. I also hit a pretty good sized mine with a mine plow in Desert Storm, fired a lot of Fifty from my M2 etc.
The Military has always been way behind the civilians on hearing protection, it's a shame,they could do a lot better. Sometimes though it's just part of the job.
I now double up on my hearing protection.
I've often wondered what the effects of the shock wave of those rounds would have?
Maximum Recommended Noise Dose Exposure Levels
Noise Level (dBA) Maximum Exposure Time per 24 Hours
85 8 hours
88 4 hours
91 2 hours
94 1 hour
97 30 minutes
100 15 minutes
103 7.5 minutes
106 3.7 minutes
109 112 seconds
112 56 seconds
115 28 seconds
118 14 seconds
121 7 seconds
124 3 seconds
127 1 second
130–140 less than 1 second
140 NO EXPOSURE
From the site:
“Each line by itself represents 100% of the allowable noise dose per 24-hour day. In other words, if you've already experienced 15 minutes at 100 dBA, you're "done for the day," and the remainder of your 24-hour period should have NO exposure above 85 dBA, and preferably should be below 70 dBA. ”
http://www.noisehelp.com/noise-dose.html
1_click_off
11-23-17, 18:22
dB safe levels have more to it than just a peak dB. There is a duration of time and cycle per second. So a single pulse of 109 might be the equivalent to 90 constant. I have a good friend that has a brother that is an Otolaryngologist. I will see if he can give some insight on this.
So the friends brother basically said if you think you should be using hearing protection, you are most likely already exceeding the need for it. Stated that gun shots which are transient noise would have each shot count as one minute of the TWA of an 8hr day.
He also stated noise standards limits are influenced by industry. The true numbers he would like used are lower than the OSHA guidelines.
He didn’t seem to want to go into a lot of detail as I assume he didn’t want his advice misconstrued or being followed without him being the one giving it directly to a client.
Impulse noise is allowed a higher dB than constant noise.
Is that for the sake of measurement or for the sake of determining hearing damage. IOW, if you were testing the efficiency of a microphone vs the impact on human ears.
He also stated noise standards limits are influenced by industry. The true numbers he would like used are lower than the OSHA guidelines.
OSHA is the 5dBA rule NIOSH is 3dB
Time to reach 100% noise dose
------- NIOSH REL OSHA PEL
8 hours 85 dBA 90 dBA
4 hours 88 dBA 95 dBA
2 hours 91 dBA 100 dBA
1 hour 94 dBA 105 dBA
30 min 97 dBA 110 dBA
15 min 100 dBA 115 dBA
I would say the firearms situation would most closely relate to the Construction Industry in these charts for civilians. The .Mil would likely be considerably worse.
https://www.cdc.gov/niosh/topics/ohl/overall.html
Is that for the sake of measurement or for the sake of determining hearing damage. IOW, if you were testing the efficiency of a microphone vs the impact on human ears.
See post 34.
See post 34.
Ok, I think I was reading your "allowed" incorrectly. So impulses are more dangerous, which is what I thought but wasn't sure how that worked.
Ok, I think I was reading your "allowed" incorrectly. So impulses are more dangerous, which is what I thought but wasn't sure how that worked.
Where are you getting impulses are more dangerous? I don’t see anything that supports that. Are you suggesting a jet engine at 130db is less damaging to your hearing than a gunshot at 130db?
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