During the MN House committee gun debate, a major point in contention was whether
Guam could tip over at the least widest part loud noises can cause hearing loss.
There were also some more intelligent questions related to the fact that suppressed weapons can still put out damaging levels of noise, (the rep was referring to the graph below) and to what degree and effectiveness various mitigation strategies exist. Several legislators wanted to hear from audiologists on the issue before voting. We had to scramble to prove
that the earth isn't flat our case before we resumed that evening. We used MN law as a source, but didn't have much time to research or even present a follow up. The bill passed regardless, but I do want to get my hands on several pieces of hard data to *prove* we are right.
Full size imageKey points to tackle, and in most cases provide solid proof:
1) That suppressors are helpful at protecting hearing even if the noise level is still damaging. Sort of like a 10 mph car crash is preferable to a 40 mph car crash. Stated another way, that 40db over the limit causes greater harm, and or chance of harm per incident than 10db over the limit. This is important for situations were ear plugs aren't possible, emergencies, and arguably deer hunting, or bird hunting in groups.
2a) Benefits for people who medically can't wear in ear plugs.
2b) Benefits for hunting dogs. Reduced chance of being gun shy, and better hearing throughout their life. I need to find a good article that talks about this.
2c) Home defense, including the children & spouses of the defendant. Obviously you can't put hearing protection on your kids when someone breaks in, and being indoors increases hearing loss from gun shots.
3) Studies of hearing loss over long periods of time for people who did use hearing protection. Edit: I found a study. Obviously working in a 110db environment with dual protection beats the same environment at 140db. Graphs, probabilities of actual harm, degree of harm, solid proof, and sources would be awesome though.
4) Various facts concerning LEO use. Our opponent claimed suppressors are only for committing murder and getting away with it.
LEO use, ~800K privatly owned suppressors, and 0 crime. (or at least ~800K tax stamps, I
will have to did look it up)
Edit to add: March 2014, there were 571,750 registered suppressors. following the trend line, and per another source, it is over 800K now.
5) Proving the way hearing protection applies. Example, a 30db suppressor and 30db ear plugs = 60db reduction. 30db plugs + 30db muffs ~= 33db-35db total reduction.
Need proof and sources.
OSHA says to add 5db to the higher of the two numbers, but to nerf the highest number. The reason being is because people don't always wear protection properly, and because there can be problems with the protection.
6) (per MicroBalrog's post below) Data, preferably .gov data, on suppressor noise reduction. (so far only third party reviews and industry marketing)
If anyone knows some good specific sources to use, it would be helpful. I have already found some
good great ones.
150-2,500 Hz (peak 900-1,500 Hz) for small-caliber weapons (rifles).
In rifle shooting, the attenuation efficiency of earplugs (16dB) or small-volume (thin) earmuffs (17 dB) was not sufficient and their use as sole protectors cannot be recommended. Instead, large-volume earmuffs should be used. Impulses from pistol and shotgun were fairly effectively attenuated both by small-volume and large-volume earmuffs.
http://triggered.clockss.org/ServeContent?url=http://archfami.ama-assn.org%2Fcgi%2Fcontent%2Ffull%2F9%2F4%2F352 Study finds hunting and target shooting causes hearing loss in men.
http://www.asha.org/public/hearing/Recreational-Firearm-Noise-Exposure/ A gold mine of awesome data.
Rifles can go over 175db, indoors increases hearing loss, severe hearing loss with as little as one shot, muzzle brakes increase noise (Dustin's note: suppressors do the same job of reducing recoil, but without the added noise).
http://www.audiologyonline.com/releases/effects-doubling-up-on-hearing-4302http://www.msha.gov/regs/complian/guides/noise/guide303.htm mining regs, refers to when dual protection is required by regulation.
http://home.earthlink.net/~dnitzer/4HaasEaton/Decibel.html chart, noise level of various things, I will look for a better one.
https://www.osha.gov/dts/osta/otm/noise/hcp/attenuation_estimation.html useful for estimating noise reduction, and for using dual protection.
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA468459 .pdf Covers sound pressure, and bone conduction.
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA454471 .pdf NIHL (Noise Induced Hearing Loss), read section 15-2.
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA501586 .pdf The limits of plugs, and doubled hearing protection. Limit caused by bone conduction of sound. Noise helmets. Bone sound conduction study.
I know MN law and CDC have some nice sites.
MN law: 116.07 sub 2(c) authorizes noise laws, standards, and limits. PCA (pollution control agency) sets the limits.
http://bulletin.accurateshooter.com/tag/silencer/http://www.silencertalk.com/results.htm Suppressor noise measurements
http://www.atf.gov/sites/default/files/assets/statistics/CommerceReport/firearms_commerce_annual_statistical_report_2014.pdf ATF, NFA, sales statistics
http://www.nssf.org/factsheets/ Many fact sheets, some are bit light IMHO.
http://www.gunfacts.info/infographics/ lots of beautiful charts and graphs
http://thefiringline.com/forums/showthread.php?t=517074 TFL thread dedicated to links, citations, and sources of info
Apparently, today’s shooters like the sounds of silence. Americans are buying and licensing more suppressors and other NFA (National Firearms Act) items than ever before. The number of NFA applications filed with the NFA Branch at ATF continues to rise. With a greatly increased staff of 25 Legal Instrument Examiners, the backlog of NFA forms has been whittled down from more than 80,000 to about 36,000. Much of the intense increase in interest in NFA items is focused on silencers. According to ATF’s 2011 Commerce in Firearms Report, as of December 2010 there were 284,087 lawfully registered silencers in the United States. As of March 2014, there were 571,750. That’s means the number of registered suppressor more than doubled in three and a quarter years. And 2015 will probably be a record year for suppressor sales.
Total number of Suppressors owned by citizens by year:
2011 285,087 January
2012 360,534
2013 494,452
2014 571,750 March
2015 ~800,000 Now
http://www.cdc.gov/niosh/hhe/reports/pdfs/2011-0069-3140.pdf National Institute for Occupational Safety and Health .pdf concerning shooting ranges.
The only potentially effective noise control method to reduce students’ or instructors’ noise exposure from gunfire is through the use of noise suppressors that can be attached to the end of the gun barrel.
Edited way too many times to add a lot more info.
