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NRR rating on hearing protection

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Forum topic by LazarusDB posted 02-23-2018 01:16 PM 831 views 0 times favorited 16 replies Add to Favorites Watch
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LazarusDB

25 posts in 194 days


02-23-2018 01:16 PM

I now have regular ringing in my ears from years of loud music, tools, etc. My hearing protection in the shop has a 30db NRR (noise reduction rating). In doing some searching I’ve found some that have a 34 rating. Anybody have or know about anything higher? Looking for the maximum rating.

Thanks.

-- Aaron - Aspiring Craftsman


16 replies so far

View Tennessee's profile

Tennessee

2873 posts in 2543 days


#1 posted 02-23-2018 01:21 PM

On earplugs, the best I’ve ever found was 34 rating. That is in the gun section of Walmart, of all places. The orange ones. I think after that, you might want to really consider a noise cancelling headset, such as the Boise or Sony. I wore one of those when I flew back and forth from Shanghai back in the day, and also used it in the buses inside Shanghai. Worked like a champ, and flowed soft music into my ears while I did not hear anything beyond my headset.
I had a Sony.

-- Tsunami Guitars and Custom Woodworking, Cleveland, TN

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Steve

442 posts in 611 days


#2 posted 02-23-2018 02:30 PM

I would do earplugs along with shooting earmuffs.

The key is to use something over the ear.

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bbasiaga

1234 posts in 2023 days


#3 posted 02-23-2018 03:10 PM

The best thing I have come up with is to wear ear plugs and then over those a pair of electronic muffs. These amplify ambient sound but then instantly cut off when loud noise occurs. You can listen to the radio, people, whatever at normal conversational levels, and then when the tools are on you have 54NRR. 20 for the muffs plus 34 for the plugs.

Buy a good set of the electronic muffs. Might cost 50 to 100 bucks. I have tried the 20dollar ones but they don’t really work.

Brian

-- Part of engineering is to know when to put your calculator down and pick up your tools.

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Lazyman

2059 posts in 1416 days


#4 posted 02-23-2018 03:56 PM

Make sure that the 34 rating you mention is NNR and not SNR. You may find that they are 34 SNR but still just 28 NNR for example. Not uncommon for them to make that confusing on purpose in their product description.

You may find that that some of the electronic active noise cancelling headphones may not work that well for power tools so read the reviews to make sure or look for a pair specifically designed for that. My Bose QC15 work very well on an airplane and in the shop will almost complete dampen the sound of my AC/Heater, for example, but for my table saw and shop vac do not really dampen the sound of my power tools any better than the regular noise blocking headphones I usually wear. They have to sort of tune the active noise cancelling for the environment they are designed for. The Bose are designed to muffle a continuous low droning rumble of an airplane for example. I suspect, though have no experience with them, that the ones designed for shooting are designed for sudden sharp blasts from a gun so might not be any more effective than regular noise blocking muffs in a shop setting either.

You will get the most bang for your buck by using some cheap expanding foam earplugs and wearing a good over the ear muff to give you an extra barrier of dampening. So just look for the highest NNR you can find.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

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JayT

5679 posts in 2239 days


#5 posted 02-23-2018 05:07 PM


when the tools are on you have 54NRR. 20 for the muffs plus 34 for the plugs.

Brian

- bbasiaga

Not really. Doubling plugs and muffs is a very good idea for additional noise protection. The combination is not additive, however, due to a couple factors. One is bone conduction, the other is that decibel ratings are exponential, not linear. Throw in the fact that the NRR are based on an absolutely perfect seal that never happens IRL and it can be tough to figure real world noise reduction.

Anything I’ve seen says adding a 26NRR or so muff to a 30NRR or so plug will give maybe a 4-5NRR bonus over the plug by itself in a real world scenario. Since sound levels double for every 3db increase, that is still a significant drop.

One of the engineers on the site is free to correct me on that.

-- In matters of style, swim with the current; in matters of principle, stand like a rock. Thomas Jefferson

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RobS888

2413 posts in 1873 days


#6 posted 02-23-2018 06:40 PM

I use these in the shop and on long flights. Great, if you put them in properly…

HEAROS XTREME 100 Pair Foam EAR PLUGS With NRR 33 Noise Canceling Hearing

-- I always suspected many gun nuts were afraid of something, just never thought popcorn was on the list.

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HokieKen

5284 posts in 1167 days


#7 posted 02-23-2018 06:45 PM

Right you are JayT. At least according to OSHA. I’m not sure exactly how the NRRs are determined but, OSHA says you have to determine a “field adjusted” value based on the level, frequency and duration of the noise exposure to which one is subjected. For adding secondary hearing protection, you get 5 more dB reduction regardless of what the NRR of the secondary protection is.

-- Kenny, SW VA, Go Hokies!!!

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jonah

1727 posts in 3327 days


#8 posted 02-23-2018 07:04 PM

If you’re going to double up, cheap foam ear plugs combined with serious 34 NRR shooting ear muffs would be my choice.

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bbasiaga

1234 posts in 2023 days


#9 posted 02-23-2018 08:23 PM

In my experience, the electronic ones made for shooting work fine on power tools. They are not noise cancelling like headphones, they have an electronic circuit that just plain cuts off the sound above 85db. You are actually listening to the world on a half second or so delay through a little speaker in The earcap. Even some random noises around the house which you wouldn’t find loud will set them off.

As far as adding the NRR, I may have over stated, but 5points addition does not sound right. Where I work, you can use double hearing protection for a shift on activities up to 125db (jackhammer, certain grinders etc, certain compressors) for an 8hr shift. That means there is at least 40nrr between our 28NRR plugs and 20NRR muffs. We must be below 85 per policy. This implies a 12 point gain. This is an osha regulated site so I am sure they have had their math checked.

That aside….It is very quiet in your double hearing protection .

Brian

-- Part of engineering is to know when to put your calculator down and pick up your tools.

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Walker

135 posts in 500 days


#10 posted 02-24-2018 05:26 AM

As JayT pointed out with hearing protection devices it is all about a good seal. The rating is only good if you have a proper fit. Everybody has a different shaped skull and different shaped ear canals. If you have a funny shaped skull, it can be difficult to get a good seal with over the ear headphones, noise cancelling type included. You have to try different ones until you find something that fits well. Vic Firth is a drum company that makes isolating headphones for drummers, that’s an other option.

And the foamies can be great until you turn your head one way or the other and the seal is broken. As for ear canals, mine are a very funny shape, they turn almost 90* upwards. The foamy plugs and the little triple flanged ones just don’t make a proper seal for me. I’m an audio engineer by trade, so I have custom molded earplugs. Known to musicians as in-ear monitors, but you can get them without a speaker inside, just the ear plug. Westone is the company I use. This requires going to an audiologist to get the molds made. One of the musicians I know has almost perfectly straight ear canals and his molded earplugs fall out sometimes. Everyone is different, and no one solution will work for everybody. Got to find something that works for you.

-- ~Walker

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Walker

135 posts in 500 days


#11 posted 02-24-2018 05:38 AM

Also I’d point out that the ringing in your ears, Tinnitus, can be caused by many different things. Some of those causes can be treated. For example ear wax build up could be a cause and it can easily be removed. Loud noises and sustained high decibel levels can cause permanent damage and tinnitus which can’t be cured. In these cases no amount of future hearing protection will stop the ringing, but can certainly keep it from getting worse. If it’s bad enough to bother you, consider seeing a hearing specialist to see if there is anything that can be done. Many health insurance plans cover visits to the audiologist.

-- ~Walker

View d38's profile

d38

98 posts in 290 days


#12 posted 02-26-2018 04:02 PM

Agree with others – best solution is well-fit plugs plus muffs.
Years ago I was active in a gun club, and a member was an audiologist. He sold hearing aids, and hearing protection to companies. He said the foam plugs do have the highest NRR, but almost no one gets them in the ear correctly to benefit from the high NRR.
For shooting, he recommended custom molded in the ear solid plugs, and a set of electronics for hunting.
I said the electronics are $1000. He replied “Pay me now, or pay me later”—implying future hearing aids—which are far more expensive than hearing protection. I purchased both the solid plugs and electronics, and they’re both great.
He sold Howard Leight muffs so he must have felt they were good muffs.
For a 1 or 2 saw cut job, I’ll put on foam plugs with a plastic connector. For larger jobs, muffs.
I use hearing protection for almost everything – mowing lawn, even running a cordless 1/4” impact driver.
Use the best you can afford. We can’t fix our ears.

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RobS888

2413 posts in 1873 days


#13 posted 02-26-2018 07:20 PM



Agree with others – best solution is well-fit plugs plus muffs.
Years ago I was active in a gun club, and a member was an audiologist. He sold hearing aids, and hearing protection to companies. He said the foam plugs do have the highest NRR, but almost no one gets them in the ear correctly to benefit from the high NRR.
For shooting, he recommended custom molded in the ear solid plugs, and a set of electronics for hunting.
I said the electronics are $1000. He replied “Pay me now, or pay me later”—implying future hearing aids—which are far more expensive than hearing protection. I purchased both the solid plugs and electronics, and they re both great.
He sold Howard Leight muffs so he must have felt they were good muffs.
For a 1 or 2 saw cut job, I ll put on foam plugs with a plastic connector. For larger jobs, muffs.
I use hearing protection for almost everything – mowing lawn, even running a cordless 1/4” impact driver.
Use the best you can afford. We can t fix our ears.

- d38


If you can see someone’s ear plugs while facing them from a foot or two they are probably not in properly.
It is obvious when they are in properly, because you will hear the sound drop out as they swell to fill the ear canal.

-- I always suspected many gun nuts were afraid of something, just never thought popcorn was on the list.

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Stumble

7 posts in 105 days


#14 posted 04-12-2018 02:36 PM

I am looking into better hearing protection and have been doing a lot of research since I already have the beginning stages of tinnitus from my time in the military.

First to correct some mistakes here…

1) NRR is not directly subtracted from the ambient decibel level. To figure out what the level is with a set of hearing protection take the NRR and subtract 7, then divide by 2. Why they do this I have no idea, but thats the formula. So a set of muffs with a NRR of 30 actually reduces the experienced sound level by 30-7=23/2=12.5.

2) Next is the sound levels we need to protect against. Almost every common wood working tool will put out sound far too loud to use without hearing protection. Routers for instance tend to hover above 110 decibels, but even tools most people don’t think of as being so loud like circular saws are between 105 and 108. Planers run about 105, table saws run about 105

3) OSHA requires hearing protection for any space where the sound pressure is over 85 decibels (pretty much just band saws, scroll saws, and hand tools). And with these types of sound levels pretty much as soon as you walk into your shop you need to put something on. But if you are firing up one of the louder tools, say over 100 decibels you really need double protection. A 100 decibel tool while wearing 30 NRR muffs (11.5 decibel reduction), is still above the threshold of hearing damage.

View Tennessee's profile

Tennessee

2873 posts in 2543 days


#15 posted 04-12-2018 04:54 PM



Also I d point out that the ringing in your ears, Tinnitus, can be caused by many different things. Some of those causes can be treated. For example ear wax build up could be a cause and it can easily be removed. Loud noises and sustained high decibel levels can cause permanent damage and tinnitus which can t be cured. In these cases no amount of future hearing protection will stop the ringing, but can certainly keep it from getting worse. If it s bad enough to bother you, consider seeing a hearing specialist to see if there is anything that can be done. Many health insurance plans cover visits to the audiologist.

- Walker


I have tinnitus. Permanent.
Little over 40 years of motorcycle riding, working 28 years in manufacturing plants, and a life long hobby of woodworking with all those loud tools. At 68 soon to be 69, I just turn up the radio…

-- Tsunami Guitars and Custom Woodworking, Cleveland, TN

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