earmuffs

[rwk]

How do they rate earmuffs, is lower number or higher number better,and which gives most protection.

 

[jbpmidas]

NRR is Noise Reduction Rating. So, the higher number offers MORE protection.

 

[Turbulent Turtle]

Also, please remember that the NRR number is in decibel, which is a logarithmic unit. In sound, an increase of 3 decibel represents a doubling of the sound level and a 10db increase (or a bel), represents 10 fold increase. A high-power rifle fired about 3 feet from your ear is around 165dB. If your earmuffs are 30NRR, that would bring the level down to 135dB which is still pretty high. Using plugs inside the muffs increases the NRR by about 5-10dB.

 

[doctear]

The highest NRR rating for ear muffs we’ve seen is with an NRR of 34.

 

[normmatzen]

turbulant turtle,

You are a bit off with your dB numbers.

Sound level is expressed in SPL or Sound Pressure Level. As it is a pressure specification, 6dB is a factor of 2 and 20 dB is a factor of 10.

Sound energy, an important value in estimating maximum noise exposure with time, indicates sound energy and 3 dB is times 2 and 10 dB is a factor of 10. But, both NRR and SPL is based on 20 log pressure 2/pressure1, where Sound energy is based on 10 log energy2/energy1.

 

[ratbuster]

turbulant turtle,

You are a bit off with your dB numbers.

Sound level is expressed in SPL or Sound Pressure Level. As it is a pressure specification, 6dB is a factor of 2 and 20 dB is a factor of 10.

Sound energy, an important value in estimating maximum noise exposure with time, indicates sound energy and 3 dB is times 2 and 10 dB is a factor of 10. But, both NRR and SPL is based on 20 log pressure 2/pressure1, where Sound energy is based on 10 log energy2/energy1.

Well that clears it up!

 

[foxguy]

turbulant turtle,

You are a bit off with your dB numbers.

Sound level is expressed in SPL or Sound Pressure Level. As it is a pressure specification, 6dB is a factor of 2 and 20 dB is a factor of 10.

Sound energy, an important value in estimating maximum noise exposure with time, indicates sound energy and 3 dB is times 2 and 10 dB is a factor of 10. But, both NRR and SPL is based on 20 log pressure 2/pressure1, where Sound energy is based on 10 log energy2/energy1.

Norm,

Thanks for sharing that, But it is pretty much a foreign language to me.
I don't use shooting muffs when shooting a rifle as I have a hard time getting my head into position behind the scope for shooting with out disturbing the ear muffs and interfering with the rifle shot.

What are most people using for hearing protection when shooting rifle. I use ear plugs, But when the guy next to me is shooting a rifle with a Muzzle Brake I don't feel they are enough protection. The Muzzle Blast is louder and I am concerned about hearing damage.

I appreciate any suggestions I get in regards to hearing protection. I'm getting a little older and already have some hearing damage and am looking to preserve the hearing I have left all that I can.

Thanks.

 

[Depart123]

Norm,

Thanks for sharing that, But it is pretty much a foreign language to me.
I don't use shooting muffs when shooting a rifle as I have a hard time getting my head into position behind the scope for shooting with out disturbing the ear muffs and interfering with the rifle shot.

What are most people using for hearing protection when shooting rifle. I use ear plugs, But when the guy next to me is shooting a rifle with a Muzzle Brake I don't feel they are enough protection. The Muzzle Blast is louder and I am concerned about hearing damage.

I appreciate any suggestions I get in regards to hearing protection. I'm getting a little older and already have some hearing damage and am looking to preserve the hearing I have left all that I can.

Thanks.

There are no inner ear plugs that are going to give you enough protection for that. To protect against that you need layers of protection, and that means muffs AND inners...good ones!

 

[johnfred1965]

I dont know the technical aspects of sound, but in my opinion, when shooting a rifle, even if it is "louder" the long barrel throws the sound away from your ears, whereas a pistol, even if it is "quieter" the short barrel allows more sound to your ears. (hope that makes some sense) My point being, I use plugs when shooting a rifle, and both when shooting a pistol, and I feel I get equal protection.

as for ratings, the green or orange plugs usually go about 33NRR while the better(not necessasarily more expensive) muffs run about 30up to 34.

http://bulletin.accurateshooter.com/tag/hearing-protection/

 

[SteveOak]

turbulant turtle,

You are a bit off with your dB numbers.

Sound level is expressed in SPL or Sound Pressure Level. As it is a pressure specification, 6dB is a factor of 2 and 20 dB is a factor of 10.

Sound energy, an important value in estimating maximum noise exposure with time, indicates sound energy and 3 dB is times 2 and 10 dB is a factor of 10. But, both NRR and SPL is based on 20 log pressure 2/pressure1, where Sound energy is based on 10 log energy2/energy1.

That is correct although there is another consideration that always messes me up and I should know better because the language of my profession is dBs.

For the 'perceived' loudness to double would take a 10dB increase.

That being said it is usually worth the money to spend a few more dollars and get earmuffs that have 32dB of attenuation rather than get the ones that have 29dB of attenuation. Unfortunately the earmuffs with better attenuation tend to be larger and sometimes present a problem clearing the stock of your rifle. In that case consider using both earplugs and earmuffs.

Now, extra credit for normmatzen; If you were to calculate the difference between two levels of power (dBm) you would use 10log10*(P1/P2). If you were to calculate the difference between two levels of voltage dBuV) you would use 20log10*(V1/V2). If you were to calculate the difference between two points in time (dB minutes) would you would use 20log10 or 10log10?

Don't overthink it. LOL

Time = money
Money = power

So you would use 10log10

 

[normmatzen]

Steveoak,

One uses 20 log (10) for pressure measurements such as P = (nrt)/V

Where energy or power such as e=1/2 MV *2
we use 10 log.

So, a linear expression is followed by 20 log where a squared function is 10 log.

And Meangreen,

layering is fine as long as the additive attenuation doesn't get above 40 dB. Your mastoid bone transfers sound level into your middle ear with an attenuation of somewhat over 40 dB. So, if you wear ear muffs with NRR of 26-28 (standard for muffs acceptable to shooters) and you use yello foamies or other good foam plugs, you will have a total of at best
(with proper insertion) 38+28 or 66 dB attenuation. However, your mastoid bone shorts that out with its 40 dB attenuation so your max is still 40 dB.

That is why I recommend using ETY-Plugs or
ER-20 plugs from Etymotic. These have pretty accurate 20 dB attenuation for a total max of 48 dB so not much over-kill wrt the mastoid bone. And, with electronic muffs, you can still hear during quiet times on the range. These have a street price of around $10. The added benefit is that the ETY-PLUG has very good fidelity so you can not only hear during quiet times, you don't get the hollow sound from occlusion effect. Using yello foamies under muffs yields the same protection as yello foamies alone so why spend money on lousy muffs?

 

[Mudeat]

Steveoak,

One uses 20 log (10) for pressure measurements such as P = (nrt)/V

Where energy or power such as e=1/2 MV *2
we use 10 log.

So, a linear expression is followed by 20 log where a squared function is 10 log.

And Meangreen,

layering is fine as long as the additive attenuation doesn't get above 40 dB. Your mastoid bone transfers sound level into your middle ear with an attenuation of somewhat over 40 dB. So, if you wear ear muffs with NRR of 26-28 (standard for muffs acceptable to shooters) and you use yello foamies or other good foam plugs, you will have a total of at best
(with proper insertion) 38+28 or 66 dB attenuation. However, your mastoid bone shorts that out with its 40 dB attenuation so your max is still 40 dB.

That is why I recommend using ETY-Plugs or
ER-20 plugs from Etymotic. These have pretty accurate 20 dB attenuation for a total max of 48 dB so not much over-kill wrt the mastoid bone. And, with electronic muffs, you can still hear during quiet times on the range. These have a street price of around $10. The added benefit is that the ETY-PLUG has very good fidelity so you can not only hear during quiet times, you don't get the hollow sound from occlusion effect. Using yello foamies under muffs yields the same protection as yello foamies alone so why spend money on lousy muffs?

ETY ear plugs:
Ad on Amazon, in the notes say:

• 
  
• Not recommended for use with impulse noise, e.g., shooting sports. Not recommended for sleeping

 

[normmatzen]

Mudeat,
Correct, ER-20/ETY-PLUGS/HI-FI are not designed for shooting.

BUT, we were talking about using them UNDER a
pair of ear muffs! Then, the 20 dB attenuation of the ER-20 adds to the 26 dB of the muff and that combination DOES protect against impulse /gun shot noise as good as it gets. Muffs by themselves and ER-20 by themselves are NOT adequate!

Just remember, the limit to protection is the 40+ dB of attenuation of the mastoid bone. So, the above combination of muff and ER-20 plug gives 46 dB but the mastoid is the ultimate limit at 40 dB. Just as muff plus yellow foamie gives a best case of about 64 dB attenuation, but the mastoid bone limits the true attenuation to 40 dB. The ER-20 - muff combo also allow one to hear conversation during lulls in shooting, but muff plus yellow foamie does not allow conversation. Plus, using yello foamie makes the muffs a waste of money as the foamie alone gives (inserted correctly) maximum protection.

 

[memilanuk]

@normmatzen everything I've read as far as industrial hear protection indicates that you cannot simply add the NRR rating of the plugs and muffs. Instead, you take the higher of the two, and add between 4-8 dB to that (5 dB is commonly cited). As such, it would be fairly difficult to with most combinations of plugs and muffs to actually achieve this 40 dB threshold that you mention, where the mastoid bone short-circuits the efficacy of the hearing protection.

 

[normmatzen]

Milinuk,
Depends on wether you want anecdotal evidence or lab data!

If you wear ear muffs with a NRR of 26, you will not be able to improve this by adjusting the fit. And, the actual attenuation will be 26-28 dB. If you wear ER-20/ETY-plugs under then, it will add 20 dB to the muffs for a total attenuation of 26+20=46. But your mastoid bone has something over 40 dB of attenuation so that is the actual attenuation you will experience.

The actual OSHA spec for hearing protection has changed some what over the years, but still is a construct of actual measured attenuation best case minus effective average fit attenuation variation. And, it is calculated by the manufacturer of the hearing protection device!

 

[memilanuk]

Milinuk,
Depends on wether you want anecdotal evidence or lab data!

Well, on the one hand we have OSHA...

5 dB can be added to the NRR of the most protective device when using both ear plugs and muffs.​

...and then we have NIOSH. Even this paper doesn't straight up add the values of the two protective devices... though I find it interesting that they cite a 15-20 dB improvement for double hearing protection, vs. single, using the most effective muffs *and* plugs... while their own chart high-lights the fairly severe reduction in efficacy for muffs worn with safety glasses. Since we are talking PPE here, we are *all* wearing eye-pro, aren't we?

 

[Knotwild]

What happens if you add a suppressor? In my case, the suppressor supposedly has a 31db reduction. So, a good set of ear muffs would reduce sound by roughly 61 db, assuming a 30db reduction with the muffs?

 

[DirtySteve]

I am here reading this with constant ringing in my ears. I should have been reading this and using better or additional protection years ago...

 

[normmatzen]

The NIOSH report quoted above was published in 2007 which was in the dark ages!

They also referred to a artificial dummy to make measurements. This refers to a dummy called KEMAR and it was developed by Knowles Electronics whose primary business is and was making microphones and "receivers" for hearing aids. This dummy was primarily made for duplicating the human ear canal along with a coupler called a Swizlocki Coupler that exactly duplicated the human ear canal acoustics and also had different inserts to duplicate different shaped ears and ear canals. A high quality microphone was connected inside this artificial ear and allowed different hearing aids to be tested . The shape of the head and torso of KEMAR caused the proper reflections and other effects on hearing from the upper body. Most Audiology testing on substitutes for the real ear use 2cc. couplers with a 1/2 inch microphone connected to them. The 2 cc. coupler is a rubber molding that costs about 50 cents and a Swizlocki is hand made and costs about $1000!
The Swizlocki coupler almost exactly copies the human ear and the 2cc coupler is a very poor copy and has a single pole response pole at 500 Hz which means it is useless for anything over 8 kHz.
Bottom line, the KEMAR wasn't designed to measure attenuation of inserts in the ear or over them as the Mastoid bone contribution isn't correct.

I stick to my comments!

 

[johnfred1965]

I don't understand any of the tech jargon in this post. Luckily, my Ear, Nose and Throat DR. shoots USPSA and 3-gun at the same club I do. When we talk hearing protection and hearing aids, we are on the same page!