Hearing loss from firearms

[rtw]

This site was referenced on "The Highroad". Thought it was interesting. Dick

http://www.freehearingtest.com/hia_gunfirenoise.shtml

[Aglifter]

I have some really nice, comfortable 30 DB reduction headphones -- never any discomfort in my ear, don't have that sore feeling, etc -- starting to wear them more when working with equipment as well -- and I have a hard time seeing that all they do is reduce the gunshots down to 130 db.  I wonder how much is caused by the actual soundwave, and how much is caused by the shockwave -- I realize I'm talking about something that isn't really seperate -- but what I mean is that I don't think the actual blast is being allowed to reach the ears w. the headphones, but I could see the vibration being transmitted by the earphones and other bones vibrating -- does anyone actually use ear plugs and head phones -- is there really a benefit?

[sslater]

Aglifter,
When shooting I wear both custom made earplugs AND good quality earmuffs.  A local audiologist had a table at a Gun & Knife show.  I think he charged $30 or so.  Friends have had custom plugs made for motorcycling at a cost of $200, so I think I got a great deal.

My left ear was damaged years ago by a friend who showed how fast he could unload a magazine from his Browning Hi-Power... about five feet from my ear!
Then after spending my working life around metal working machinery in engine manufacturing plants, I had a hearing check performed.  Surprise!  Left ear was bad and right ear wasn't much better (65 & 60 dB loss.)
Tha audiologist recommended that I wear double hearing protection around firearms, and earmuffs for ANY work around lawnmowers, hedge trimmers, woodworking power tools, even vacuum cleaners.  Yes, I help out around the house.  It makes firearm purchases much easier.  

Today, when people greet me my response is the same for friends and strangers alike, "Huh?"  

[tracker]

I also use earplugs [not custom] and earmuffs--always have
because I don't want to incur any more cochlea damage.

[Michigunner]

I also use plugs and ear muffs.  

With constant ear ringing, I don't want it to become worse.

I once ignored vision protection, but after being struck in the face by ejected rounds, the message was clear.

That P3AT must have needed some tape on the grip.  That is, the pistol apparently  twisted in my hand while firing, such that the ejection port was pointed the wrong way.

I've heard others describe how they were struck by ejected rounds.  Perhaps it is an extreme case of limp wristing.

Bill

[theirishguard]

HUH??
I also use a pair of custom ear plugs and ear phones.
Tom

[tracker]

There is an excellent article on hearing protection im the
Feb/Mar 2006 issue of "Handguns" magazine. It gives the
comparative decibels of most popular calibers; turns out
the 9 mm. asnd 357 magnum are only 10-15 decibels apart.
The article also covers some excellent protective devices.

[Michigunner]

Thanks, tracker.  I'll try to check that out.  I've been debating about getting an electronic ear muff.

My long experience in amateur radio tells me that if you double the transmitter power, there will be a three db difference.  One db is the least change that the ear can detect.

On the subject of a 15 db difference between the two guns, to the best of my knowledge that would be like doubling the power five times.

So if you started with some power level called 1, if you double it five times,  it would be 2, 4, 8, 16, 32.

The way I see it, the .357 would be 32 times as loud as the 9 mm.

If this reasoning is faulty, someone please help.

Bill

[sslater]

Michigunner,
Your math is correct, but a little misleading.  
A 15dBA difference in sound intensity does require 2⁵ (32 times)  increase in sound power.  That doesn't mean, however, that the the sound is 32 times as loud.

I found a really good website,
http://www.phys.unsw.edu.au/~jw/dB.html that explains how the dB scale works.  
Best of all, there are three sound tracks which you can listen to.  The first one shows a broadband sound (I think a gunshot is single frequency..) decreasing by 3 dB at a time.  So count off five bands, then click the demo.  As you can hear, there is a noticeable difference between the largest bar and the 5th bar.  Try the other soundtracks, which are spaced closer together.  Much harder to pick out the individual steps.

Bottom Line: 10 or 15 dBA represents a large increase.  Continued exposure to anything in the range of a handgun's sound intensity will damage your hearing.

(Take a look at road tests in Road & Track magazine, for instance.  If there's less than 3 DBA difference between two modes, an average observer won't be able to tell the difference.  For instance, I'm looking at a road test of the 2006 Pontiac C6 GTP.  Interior noise was measured as 66 dBA at 50 mph, and 70 dBA at 70 mph.  From personal experience you know it's a rare car that's not noisier at 70 than 50 mph, so the theory makes sense.)

[Michigunner]

Thanks, Steve.  It looks very interesting.  I'll check it out.

Upon further thought, I guess the recipient of a 15 db change would hear the least detectible change (1 db), then another least detectible change (1 db), until this occurred 15 times.

Of course, the total change would appear to occur instantly.  I recognize there would not be 15 steps in the process.

My guesses are based upon amateur radio experience, where we learned that doubling the transmitter power would result in a 3 db change for the receiving person.

Meanwhile, the teachers were the same people who taught us that atoms looked like little solar systems.  Now I'm not so sure what to believe.

Bill