Sound level
- Thread starter greentips
- Start date
I don't test at the ear. One complication with at ear testing is that it depends on the firearm's mechanism. Noise at the ear is influenced by whatever comes out of the ejection port. I can tell you that a few years back Crane tested most of the top 556 cans and discovered that while many of them were hearing safe at the muzzle, none of them were hearing safe at the ear because the increased back pressure from the can drove so much extra noise out the ejection port.
Then there was the test done in the US recently where the guy metered different muzzle brakes and FH's. He found an 8 dB variation between the standard A2 FH and the loudest brake. If we remove all the variables like semi-auto action and muzzle brakes, IIRC the noise level drop from muzzle to ear is roughly 6-8 dB.
So to a certain degree barrel length is irrelevant because the action mechanism and muzzle devices will have a much greater effect on driving sound to the shooter's ear.
Is there a specific question you have that I might be able to answer for you? Or what is it that you are trying to accomplish?
I am curious to figure out if a 20" rifle is less damaging to hearing than say a 10.5" carbine ( in convention layout), say in an open area in case ear protection is not worn. I understand firing indoor ( with any lengths of barrel) will be more damaging as the pressure waves get reflected and the duration of the harm is longer.
I wonder if conventional ear plugs are sufficient, especially for shooting short barrel rifles, in the long run to avoid damages.
I wonder if conventional ear plugs are sufficient, especially for shooting short barrel rifles, in the long run to avoid damages.
I think it would be completely dependent on the brake or compensator you use.
I have a 12.5 inch AR and with a Rainier Arms mini comp I need double hearing protection but with a linear comp or a PWS triad simple ear plugs are fine. My SL8-4 with no muzzle device is loud but almost tolerable without plugs at all in an open area, you still need them but at least your ears don't ring after a single shot.
I think there are too many variables to have any useful numbers that would be relevant to consider a general average spl.
I have a 12.5 inch AR and with a Rainier Arms mini comp I need double hearing protection but with a linear comp or a PWS triad simple ear plugs are fine. My SL8-4 with no muzzle device is loud but almost tolerable without plugs at all in an open area, you still need them but at least your ears don't ring after a single shot.
I think there are too many variables to have any useful numbers that would be relevant to consider a general average spl.
The difference in sound level at the shooter's ear is not going to be a whole lot between a short barrel and a long barrel but that is kind of moot because the long barrel is more than loud enough to cause hearing damage even through your hearing protection. Without hearing protection all centre fire rifles will damage your hearing regardless of barrel length.
Dr Matthew Parker Branch did a study where he showed that common ear protection is not sufficient to reduce the sound level to less than 140 dB. You can read a précis of the study here. http://oto.sagepub.com/content/144/6/950
This means that the CDN ban on sound suppressors is actually forcing all shooters to damage their hearing because the ear protection we are forced to use is not capable of protecting our hearing sufficiently.
Personally I am finding that I cannot tolerate rifle fire indoors without double plugging. I used to be able to but it really bothers me now. It would make the sport so much nicer if we could suppress everything.
Then Wendy says "then just don't shoot at all if you don't want to loose your hearing", grins and walks away.
So what is required to completely protect our hearing while respecting the law? I use the little stryrofoam ear buds or normal ear muffs depending on what I have on hand. The noise level doesn't seem to bother me but if I'm doing damage I'm a little concerned.
I imagine the adequate level of protection varies greatly depending on what you are firing, how it is braked, and if you are indoors or near something like a wall that will increase pressure.
You may be able to get away with less protection with a 20" AR with a birdcage flash hider than you would with an aggressively braked .338 Lapua or .308 Win.
That said, you are never unwise to double plug with high quality plugs and electronic hearing protection when shooting any centerfire rifle or big bore handgun.
I have made several mistakes with hearing protection before that are slowly starting to show... Including having my muffs on incorrectly when I cracked off a shot of 500S&W, and a very dumb decision where I decided to fire a shot of .338LM without any protection because I had forgotten ear protection at home. Never again, I had serious ringing for 5 days in both ears.
Plug up every time, hearing damage is cumulative and won't come back, and i am sure a lot of members here can attest to that.
You may be able to get away with less protection with a 20" AR with a birdcage flash hider than you would with an aggressively braked .338 Lapua or .308 Win.
That said, you are never unwise to double plug with high quality plugs and electronic hearing protection when shooting any centerfire rifle or big bore handgun.
I have made several mistakes with hearing protection before that are slowly starting to show... Including having my muffs on incorrectly when I cracked off a shot of 500S&W, and a very dumb decision where I decided to fire a shot of .338LM without any protection because I had forgotten ear protection at home. Never again, I had serious ringing for 5 days in both ears.
Plug up every time, hearing damage is cumulative and won't come back, and i am sure a lot of members here can attest to that.
I can remember years ago when I had an experience with "insufficient" hearing protection at a day at the range.
We were shooting a .223 short barreled (18") rife on a VERY COLD day.
The air was very dense from the cold temperature and I had my ears ring for two days after.
Cold air can make the problem worse
NEVER AGAIN has that happened to me. I don't use tools in the shop or cut the grass with the lawn mover without proper hearing protection.
Cheers!
B
P.S.
And don't buy CHEAP hearing protection at Princess Auto. Buy a reputable brand,
We were shooting a .223 short barreled (18") rife on a VERY COLD day.
The air was very dense from the cold temperature and I had my ears ring for two days after.
Cold air can make the problem worse
NEVER AGAIN has that happened to me. I don't use tools in the shop or cut the grass with the lawn mover without proper hearing protection.
Cheers!
B
P.S.
And don't buy CHEAP hearing protection at Princess Auto. Buy a reputable brand,
The nominal all-burnt length for .223 is 11".
Short barrels have a larger amount of unburnt or incompletely burned propellant that ignites outside the bore. This results in greater flash and noise.
The exact amount depends on the propellant, bbl length and muzzle device.
Short barrels have a larger amount of unburnt or incompletely burned propellant that ignites outside the bore. This results in greater flash and noise.
The exact amount depends on the propellant, bbl length and muzzle device.
The most that we can do is double plug. I suspect that is sufficient but I don't know for sure. Unfortunately we do not have the option of anything better or more effective. The laws of the land force you to damage your hearing while shooting centre fire rifles. Thats nice isn't it?
As mentioned by others, double plug. I use foam ear plugs (custom are better) and quality ear muffs (Pro Ears Gold - 30db NRR). If you care about your hearing but are short on cash, use the cheap Peltor Ultimate 10's or equivalent 30+db NRR ear muffs over at least foam plugs. For electronic, the often recommended $50 Howard Leight are ones to avoid. At only 22db NRR, you aren't doing your ears any favours. My wallet can heal, my ears can't. Choose wisely.
We had a discussion recently at work and loud noise, including gunfire with the HSE guys. From their available data, even the most expensive form fitted, custom made earplugs will only protect from 108-120db WHICH IS NOT ENOUGH. According to their data (tested at ear or muzzle I do not know) gunfire tested on average in the 120-140db range! I would think a .338lm or shorty AR with a brake would be even higher.
Based on what I saw it reconfirmed my thoughts to always double up on hearing protection.
Based on what I saw it reconfirmed my thoughts to always double up on hearing protection.
As Suputin pointed out, it's a pretty complex question.
Sound levels are different at different locations. It requires several microphones and a suitable test facility and there are a number of other variables as well, such as the type of firearm, cartridge, muzzle device, etc.
Hearing damage is also cumulative.
I wear full cup electronic defenders if I'm shooting a few rounds. For prolonged exposure I use custom moulded with my Peltor's set to plug mode.
Sound levels are different at different locations. It requires several microphones and a suitable test facility and there are a number of other variables as well, such as the type of firearm, cartridge, muzzle device, etc.
Hearing damage is also cumulative.
I wear full cup electronic defenders if I'm shooting a few rounds. For prolonged exposure I use custom moulded with my Peltor's set to plug mode.
Suppressed gunfire is in the 120-140 dB range. Unsuppressed gunfire ranges from around 155-165 dB at the muzzle. That will drop maybe 6-8 dB at the shooter's ear.
The vast majority of sound levels quoted these days were collected with unsuitable equipment and are much too low. 140 dB is the limit for hearing damage from impulse noise and it is also the pain threshold for noise. That is noise above that will cause physical pain to the ears. Shoot a centre fire rifle without hearing protection and ask yourself if that hurts. If so then it is well over 140 dB.
Those SPL's are roughly 5-10dB too low. Likely because they were collected with a sound meter than was not fast enough to capture the event peak. There are only a few systems available today that are fast enough for this kind of work and they are either difficult to find or expensive or both.
This is like the one I use.
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