FF112173
Member
If I'm shooting at an outdoor range are the foam plug types rated at say NRR 32 good enough or must you use ear muffs as well?
Let's talk hearing protection
- Thread starter t bell
- Start date
Rastoff
US Veteran
Yes, the foam plugs are as good as you can get. While adding more ear protection is always better, there is a point of diminishing returns.
Noise Reduction Ratio (NRR) is based on a logarithmic scale. So, using a 23dB plug with a 23dB muff does NOT give you double the protection.
On a log scale power is cut in half every 3dB. So, an ear plug that is 3dB will cut the sound in half; 50% reduction. Now, increase that to 6dB and you cut it in half again for a total of 75% reduction. Raise it another 3dB to 9dB and you've reduced the sound 87.5% and so on. It looks like this in a chart:
So, as you can see, once you reach about 18dB of reduction, any more and you're not making a significant advance in protection.
Now, that doesn't tell the whole story. If you only look at the chart I made, it looks like a 24dB NRR would about cancel out all sound. Unfortunately, that doesn't tell the whole story. Ear protection is not as simple as one number. Sound is made up of many frequencies. Each frequency is reduced a different amount depending on the device. This is why the NRR is called a weighted average. While a plug might be rated at 24NRR, that is an average across the frequency spectrum. It might actually be 35dB at 200Hz and only 10dB at 5KHz. So, to really know what kind of protection you're getting, you have to look at how it performs across the spectrum.
Further, ear protection doesn't work the same for everyone. If you wear glasses with muffs(and you should), the arm of the glasses breaks the seal around your ear. This can reduce the protection value by as much as half. So, those great electronic muffs you just bought that are rated at 24NRR could be as low as 12NRR because of your glasses. This obviously won't happen with plugs.
Even plugs are not perfect. As you move your jaw the shape of your ear canal changes. If your plugs are not fit properly they won't protect as well as you might think.
Noise Reduction Ratio (NRR) is based on a logarithmic scale. So, using a 23dB plug with a 23dB muff does NOT give you double the protection.
On a log scale power is cut in half every 3dB. So, an ear plug that is 3dB will cut the sound in half; 50% reduction. Now, increase that to 6dB and you cut it in half again for a total of 75% reduction. Raise it another 3dB to 9dB and you've reduced the sound 87.5% and so on. It looks like this in a chart:
3dB= 50%
6dB= 75%
9dB= 87.5%
12dB= 93.75%
15dB= 96.875%
18dB= 98.44%
21dB= 99.22%
24dB= 99.61%
6dB= 75%
9dB= 87.5%
12dB= 93.75%
15dB= 96.875%
18dB= 98.44%
21dB= 99.22%
24dB= 99.61%
So, as you can see, once you reach about 18dB of reduction, any more and you're not making a significant advance in protection.
Now, that doesn't tell the whole story. If you only look at the chart I made, it looks like a 24dB NRR would about cancel out all sound. Unfortunately, that doesn't tell the whole story. Ear protection is not as simple as one number. Sound is made up of many frequencies. Each frequency is reduced a different amount depending on the device. This is why the NRR is called a weighted average. While a plug might be rated at 24NRR, that is an average across the frequency spectrum. It might actually be 35dB at 200Hz and only 10dB at 5KHz. So, to really know what kind of protection you're getting, you have to look at how it performs across the spectrum.
Further, ear protection doesn't work the same for everyone. If you wear glasses with muffs(and you should), the arm of the glasses breaks the seal around your ear. This can reduce the protection value by as much as half. So, those great electronic muffs you just bought that are rated at 24NRR could be as low as 12NRR because of your glasses. This obviously won't happen with plugs.
Even plugs are not perfect. As you move your jaw the shape of your ear canal changes. If your plugs are not fit properly they won't protect as well as you might think.
It's important to do use a calculation method to determine accurately the actual exposure to your ears. For those interested, the US Department of Labor has its OSHA method of calculation, which manufacturers of hearing protection use as guidelines. Note that using 100dBA in the example is for workplace noise and that gunshots are of the order of 145-155dBA average depending on caliber/ firearm.
Here's the link: http://www.osha.gov/dts/osta/otm/noise/hcp/attenuation_estimation.html
I'm not loving the recommended method to use 50% NRR when doing the calculation. The message is that the more protection one uses, the better.
Here's the link: http://www.osha.gov/dts/osta/otm/noise/hcp/attenuation_estimation.html
I'm not loving the recommended method to use 50% NRR when doing the calculation. The message is that the more protection one uses, the better.
FF112173
Member
This just reached a level of difficulty I wasn't prepared for.
Rastoff
US Veteran
Sorry, my inner geek woke up. I'll try to beat him back down.
The take away is, more protection is better, BUT, learn how to use it properly. Hearing protection that isn't worn properly is the same as not wearing it at all.
The take away is, more protection is better, BUT, learn how to use it properly. Hearing protection that isn't worn properly is the same as not wearing it at all.
How well do these work?
- Joined
- Sep 19, 2012
- Messages
- 3
- Reaction score
- 1
Same here, low profile ears and plugs. Works great.
HOPSTER
Member
I didn't think about the glasses interfering with ear muff seal - very good point, and a good reason to learn to like my silicone molded plugs.
I spent one summer using an underwater cutting torch while working dive salvage. The torch itself used oxygen burning magnesium rods (commonly called Broco Torch) and often the residual oxygen bubbles would explode as secondary burning of whatever gas products were being produced. These were much louder than shooting without hearing protection and I'm certain that I have some permanent damage. Working around jet engines for the last 28 years hasn't helped either ....
I thought that the noise from shooting was measured differently that the noise from factories, jet engines, etc.
In other words, a shock wave from gun blast would be best measured differently from loud music etc. I haven't searched for that reference. This has been a very informative thread !
I spent one summer using an underwater cutting torch while working dive salvage. The torch itself used oxygen burning magnesium rods (commonly called Broco Torch) and often the residual oxygen bubbles would explode as secondary burning of whatever gas products were being produced. These were much louder than shooting without hearing protection and I'm certain that I have some permanent damage. Working around jet engines for the last 28 years hasn't helped either ....
I thought that the noise from shooting was measured differently that the noise from factories, jet engines, etc.
In other words, a shock wave from gun blast would be best measured differently from loud music etc. I haven't searched for that reference. This has been a very informative thread !
Chubbs103
US Veteran
Like a lot of folks here, I wish I was better about hearing protection 20 years ago.
Depending on the role I am playing at work, I am regularly around a lot of noise. I've worn the Peltor muffs and was pleased. Last year a had a custom fit set of plugs made with the ability to tie a radio into them. They are absolutely great. They were uncomfortable if worn for a long period of time, but I have gotten used to them now.
I've gotten to the point that I regularly wear hearing protection with power tools. That is something I used to be really bad about.
I have seen an interesting and somewhat unsettling trend in some of the posts. Many people seem to think that the muffs are a step up in protection from the plugs. This is usually not true (although there are some exceptions).
Double up if it gets loud. Start early in your shooting career and don't get lax about it. Hearing loss compounds over time.
Chubbs
Depending on the role I am playing at work, I am regularly around a lot of noise. I've worn the Peltor muffs and was pleased. Last year a had a custom fit set of plugs made with the ability to tie a radio into them. They are absolutely great. They were uncomfortable if worn for a long period of time, but I have gotten used to them now.
I've gotten to the point that I regularly wear hearing protection with power tools. That is something I used to be really bad about.
I have seen an interesting and somewhat unsettling trend in some of the posts. Many people seem to think that the muffs are a step up in protection from the plugs. This is usually not true (although there are some exceptions).
Double up if it gets loud. Start early in your shooting career and don't get lax about it. Hearing loss compounds over time.
Chubbs
So do I, except first I remove the hearing aids from both ears. (That's a hint for you young guys; once your hearing is gone, you can't get it back. Take care of it while you have it.)
Rastoff
US Veteran
Not measured differently, but certainly different.
Noise from a gun is impulse noise. Noise from a jet engine is continuous noise. There are ear protectors out there that are effective against impulse noise, but not continuous. An example of that is the EP3. If you leave the hole open, it's not very effective for continuous noise. It has to do with the way the noise blocker works.
cockerpoodle2
Member
- Joined
- Aug 27, 2010
- Messages
- 79
- Reaction score
- 54
I do most of my shooting at an indoor range (it rains up here in the Northwest). I wear silicone plugs and (passive) ear muffs. I'm thinking about getting electronic muffs. Can someone tell me what happens when the battery wears out. Does the noise suppression go away ? Is there a fail-safe function (full noise suppression with dead battery) ?
Also, I read about foam plugs with a valve that allows normal sounds but closes with loud ones. Do they work ? Do they exist ?
Thanks in advance,
Cockerpoodle
HOPSTER
Member
I used a set of "analog" style valved ear plugs in the early 90s working around jets. I think they are still sold by "North" Company. The diaphragms are in a small metal drum which can be removed from the ear plugs for cleaning the plugs. They worked fine for me and I have used them shooting also.
I do most of my shooting at an indoor range (it rains up here in the Northwest). I wear silicone plugs and (passive) ear muffs. I'm thinking about getting electronic muffs. Can someone tell me what happens when the battery wears out. Does the noise suppression go away ? Is there a fail-safe function (full noise suppression with dead battery) ?
Also, I read about foam plugs with a valve that allows normal sounds but closes with loud ones. Do they work ? Do they exist ?
Thanks in advance,
Cockerpoodle
They enable hearing conversations but louder noises "close" a valve of some sort, I think by using a diaphragm. They do not work like the electronic ones at all, if there is a loud noise present, then they seal off all noise, till the loud noise stops. I will try to find out more info on them.
EDITED : Heres a link. They are called Sonic II and not considerd adequate for shooting. There is an updated version for shooting. If you search for "North Sonic II" you will find the new model:
http://shop.precisionweb.com/browseproducts/Sonic-II-Hearing-Protectors.html
Last edited:
Cockerpoodle, the batteries only power the electronic muffs' ability to amplify ambient sounds you want to hear. When the batteries die, you're left with the function of a regular pair of muffs.
I haven't looked at every brand and model, but the 6-7 I've seen have lower NRR ratings than non-electronic models. I don't shoot often enough to justify the cost. I'll cheap out and keep using my plain ones with a higher NRR rating.
I haven't looked at every brand and model, but the 6-7 I've seen have lower NRR ratings than non-electronic models. I don't shoot often enough to justify the cost. I'll cheap out and keep using my plain ones with a higher NRR rating.
cockerpoodle2
Member
- Joined
- Aug 27, 2010
- Messages
- 79
- Reaction score
- 54
Thanks guys-- I appreciate the information. I have ordered a set of uprated Sonic II plugs. I think I will also get some electronic muffs. Recommendations ?
Cockerpoodle
Lil' LadySmith
Member
I'm another using the Sonic Defenders. I have a set of the EP4 ones that i use at work and have been really pleased. They seemed to work well when shooting outdoors too. Since I took the EP4s to work I got a set of EP5 and EP7s for shooting. (not sure if I'll like the 7s due to the foam covers)
I have a hard time getting plugs in my ears and never could stand headphone type ones. (ears and head are too small) The Sonic Defenders though actually FIT in my ears and are pretty comfortable. At work I put them in when I get there and take them out when I leave and sometimes forget they're in.
