Home Forums Hunting & Shooting Ask The Gunwriters sound level relationships

Is there a sound\noise\decibel level formula for different loads of a cartridge?

I didn't see any tables of data, either.

If there is, I can't find it after lots of looking on the web. Even a ball park value would be of help.

As far as I know, nobody has taken the time to produce the chart you are after. There are so many types that it would be hard to make a coherent list.

FWIW, the 30-06 is reputed to produce about 170 dB. Shorter barrels produce more noise, all other factors equal.

The best sources I have say that continuous noise above 105 dB is clearly harmful, and impulse noise like a rifle shot above 140 dB is harmful. So yer plugs need to be 30+ dB, and most of them aren't.

Are the NRRs of plugs and muffs additive?

It's intuitive that they would be, but I wonder if there is some factor I'm not aware of.

The dB scale is logarithmic so IIRC values would need to be calculated. Doubling the volume only increases the dB reading by about "3".
25dB + 25dB = 28 dB
Here's a quick calculator-
http://www.anvtech.com/calcul-1.html
Doesn't seem to like adding negatives though.

I saw one awhile back . Google " hearing impairment from shooting " . The chart will be on one of the first links that comes up .

It had enough different rifle cartridges shown to approximate the rest of them .Also has charts for handgun and shotgun .

IIRC a 30 06 with 24 in barrel is exactly the same as a 12 ga. shotgun with 26 in barrel .

www.earsoftexas.com/hearingear_disorders/shooting.htm - Cached

Here it is . Notice the 375 w/ muzzle brake and 18 in. barrel compared to 06 with same length barrel .

You have to click on "sound intensity of various firearms "

Pretty close.

As 86thecat has said, the scale is logarithmic. Doubling the sound power (turning the stereo up so that 4 watts are delivered to the speakers instead of 2) adds very close to 3 dB. 10 times as much sound power is 10 db. So 20 dB is 100X the sound power, and 30 dB is 1,000X the power. Muffs that reduce noise 26 dB reduce sound power 400X.

Rocky is the board expert on ear protection. Maybe he will weigh in here.

It's surprisingly difficult to get plugs in right, and once they are in, difficult to get them out. I think that most people who wear plugs don't get the full benefit of them.

One thing I have not seen done in this market is active damping. In that scheme, microphones on the headset pick up outside sound and use it to cancel sound inside the headset. That's part of what they do with Bose headsets, so you can hear music while on a plane. You can pick up another 10 dB or so that way, which would be a worthwhile improvement over the usual 26-29 dB earmuffs that are common.

Sound pressure level is directly related to the pressure of the propellant gas at the moment the bullet uncorks the barrel. Muzzle brakes make the sound much more intense.

curdog: Neat link. Thanks for posting.

Thanks that is of some help. I was hoping for what change there was between reduced and full loads but even a .223 is 155 spl so maybe there isn't that much difference.

It is too bad .22LR is not listed.