On the same scale as that "Sprint Supersonic Scream" commercial...
Posted on 10/31/2014 4:41:50 AM PDT by LouAvul
I asked an audiologist yesterday, but she didn't know.
I always thought the NRR on a pack of ear plugs meant that was how much they reduced the noise.
Then I read that to determine the true noise reducing effect, one subtracts seven from the NRR and divides by two.
That means if my plugs have a NRR of 27-7/2=10. So if I'm firing a weapon = 169dB and only wearing earplugs, the noise hitting my ears is 159dB. That's still well above the instant damage level. Even wearing muffs, you only add 5dB to the protection which still equates to instant damage.
Is this accurate, because if it is, it's no wonder so many shooters have to yell at each other.
Oh, and the audiologist determined that I have mild hearing damage in my left ear and mild to moderate in my right. Dunno exactly what to blame. Loud music. Construction equipment. Bird hunting.
I don’t see how to apply that information to designing equipment, providing sound level warnings and selecting appropriate hearing protection.
For most people interested in the topic, they want to know when and where to protect, and how much protection is needed.
You still need to nod and say "yep" at the appropriate places. Wrong timing of that sets the ending back another 15 minutes....
Mark Twain claimed he had a terribly hen pecked uncle who had gone deaf years ago. However he could still hear the word “whiskey” whispered three rooms away with the doors shut.
Yeah my hearing loss is driven a lot by tinnitus. The tinnitus gains and lowers inconsistently. I explain this to my wife often. It is mostly true.
I did a fair amount of research in a former business in this area. One day I noticed my left ear had worse hearing than the right. I wondered why. I eventually had a ‘lightbulb moment’ and took my meter for a ride in my rig and checked the SPL with the window down.
Try it sometime. I now keep an earplug in my car for my left ear.
After decades of using foam plugs and muffs I got some custom molded ones made. Huge difference in noise attenuation and comfort. It’s worth every penny.
The first part of it is understanding the frequency range and frequency response of your measuring equipment - most of the cheaper (sub 1K) dB meters fall flat around 300 Hz. That isn’t helpful to people who are exposed to 10-100Hz noise on a regular basis because you will never measure it with equipment that doesn’t consider it.
I have been looking in vain at 5K plus cost dosimiters and can’t find specs that state what the frequency range is, which also holds true for lesser meters. Most of the meters I have looked at don’t go beyond 140dB either.
What might be actually useful is a band analyzer that does have specs: http://www.extech.com/instruments/resources/datasheets/407790.pdf
That has a 25Hz ~ 10kHz frequency range (so that misses a lot of the highs), but real truly deafening SPL levels will come from within this range, the dB in high frequencies is what will cause damage in the high frequency range.
It is really about understanding the area of concern and the equipment used to measure the response of said concerning item.
The measurement is actual tested noise reduction in a lab.
Subtracting 7 is a fudge factor assuming an imperfect placement of the hearing protection.
Dividing by two is a safety factor introduced by government to further protect workers.
If you use the protection with attention to getting a good seal, you will get close to advertised noise protection.
That being said, even imperfect protection is better than none, always cover your ears and wear eye protection at the range. If I’m in an indoor range, I use plugs and muffs, it helps me shoot better when someone next door is shooting a magnum.
I had tinnitus for years after doing lots of noisy stuff without protection. Thankfully it has almost completely stopped. I now keep earplugs handy everywhere. Haven’t fired a gun without muffs and or plugs for decades.
Man I would love that. I've been careful for more than a decade. Too much damage done before that.
After 20+ years around Navy turboprops and jets as well as decades of shooting, at 65 y/o my audiologist tells me I have virtually no hearing loss. I do have some tinnitus but not much. I attribute this to the dedicated use of the military style, yellow, cylindrical E-A-R Classics made by 3M. They can be a bit coarse and a bit difficult to insert but fwiw I think they’re the best you can buy. 30 pair on Amazon for about $7.00.
Or you end up seeing a new appliance or something in the house that you don’t remember discussing.
Plane tickets, what plane ticket? What do you mean a two week vacation in the Bahamas? I got work to do!
On the same scale as that "Sprint Supersonic Scream" commercial...
I read somewhere that wearing multiple forms of hearing protection isn’t additive. It’s only as good as the highest rated device. I keep a container of the highest rated foam ear plugs I can find and wear them when running power equipment.
A lot of people do not know how to insert ear plugs properly.
Check this out, it may help out:
http://trace.wisc.edu/docs/2004-About-dB/
This is not exactly the problem.
The weighting is due to the natural resonance frequencies and damping ratio of certain ear structures. Some are more sensitive than others to breakage and thus hearing loss.
As a Bass Player, you know that you need three times the power than a guitarist does. Their 100-watt rig is perceived to be as loud as your 300-watt rig. This is the reason that bass players tend to be bigger guys from hauling around all that much heaver gear.
MarkBass capitalizes on physically smaller but more efficient rigs because older bass players can’t haul the rig around anymore. 8X10 cabs are dirt cheap for this reason.
I have an 18 inch cab that never leaves the house anymore.
That high pressure wave would tickle my insides while firing. Was long ago and I don’t recall using ear plugs at the time. All we did was open our mouths and cover our ears with our hands. That M29 made about 180 dB.
I don't know about "need," but I certainly get less than I want, even with earplugs.
I am more interested in protecting against damage than perception of sound.
I appreciate the information, but that seemed to be more of the same basic.
I don’t mean to complain about helpful info. I was just hopeful for info that corresponds to providing protection and setting limits for required hearing protection of other.
Not only do I wear hearing protection in industrial facilities, I’ve been called upon to help make recommendations for signage to set limits for others.
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