Decibel difference between calibers

M

_Muad'dib_

New member
I hear how the .357 is so loud, especially if you had to shoot indoors with it. Does anyone know the difference between the decibel levels of the 9mm/.38/357/.45? I'm just kinda curious how much difference there really is. If you know more calibers than that, might as well list them also :)
 
Take the values in that table as relative numbers, as the coefficient of loudness for a single impulse sound varies widely based on how one defines the conditions of measurement.

Also, bear in mind that a 3 dB increase in loudness represents a doubling of the sound pressure level.
 
I don't understand how a 3 Db increase can double the sound level. Can you explain or give me a website that will explain it? If that were the case though then a .357 is much louder than a .45
 
The Decibel Scale is Logarithmic - for every 10 db increase in the scale the energy level is 10 times the previous level!!

On the decibel scale, the smallest audible sound (near total silence) is 0 dB. A sound 10 times more powerful is 10 dB. A sound 100 times more powerful than near total silence is 20 dB. A sound 1,000 times more powerful than near total silence is 30 dB
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http://www.howstuffworks.com/question124.htm

So, there is a noticeable difference and resultant damage between a 150 db firearm cartridge and a 153 db cartridge, with MUCH more potential damage for the louder cartridge.
 
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Here's a website with some cartridges listed:

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

hope this helps.
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From that link -->

Hearing loss is not fun and can be prevented.



Those that don't suffer from hearing loss may think that sounds just get quieter and quieter as you go deaf. NOT SO! They should call it hard of UNDERSTANDING. as the cilia in your inner ear die, the body compensates and uses the next nearest ones. You get a reduction in frequency discernment . The sonic pressure physically breaks the cilia and leaves debris that keeps others from vibrating as they should. I can "hear" fine, I just can't understand a damn thing that is said at some frequencies. Especially the female voice., which pisses my wife off to no end. In loud areas like a bar, I can't understand anything, but can sometimes pick out a conversation across the room. And in some cases (like mine), sounds will seem to be LOUDER than normal. A kid screaming while playing sounds like an explosion and feels like an ice pick in my head.

Don't get me started on the tinnitus (ringing). If you have a loud computer fan, put that next to your head 24/7, but change the pitch up half way to a mosquito. That's the brain's way of dealing with cilia that have been permanently killed - it "imagines" they are still putting out vibrations.

I can pretty much trace 50% of my problems to just a few shots w/o protection. The rest to loud work environments and old age.


Sorry to be on the soap box but it's personal.:o



Back on topic --> The magnum rounds are not only louder, but the sound goes on longer. Where a 25acp is 155 db and a 357mag is 163 db, that tells only part of the story. The louder sound does damage at a greater rate and also goes on for a longer time and because of it -- it does damage far greater than just the 8x you might think from the DB change. Double whammy. Indoors (especially in a house), the sound is reflected back off the walls several times. The first 3-4 reflections are all above the level that causes damage, so it's like hearing 3-4 shots when it comes to ear damage.

oh, don't forget that after about 140db your ears basically shut down and you can't tell the difference between 140 and 165db -- but the damage level is different.
 
+3dB is a doubling; +6dB is x4 from the original...

... and so on.

Conversely, -3dB is a halving of sound level.

As others noted, it's logarithmic, not linear.

So, a 161dB report is 4x louder than a 155dB report.

10dB is x10, not x100. I think that was a typo in one of the previous posts, since he had it correct elsewhere in the same post.
 
Side Note:

Muad'Dib, since your name is a Word of Power, you might want to do some searches on acoustics and decibels so you can verify it for yourself.

And yes, cougar gt-e is correct about what happens in confined spaces. Same results occur with sonar ducting.
 
My very unscientific analysis revealed that 10mm is way louder than 9mm. I forgot to put on my hearing protection for 1 round of 10mm, and it was painfully, shockingly loud......compared to the time I forgot to put on my hearing protection for 9mm.
 
When I shoot I use both the foam ear plugs and a headset, trying to protect the hearing I have left and not get the tinnitus any worse. :(
 
Here's another thread where we discussed this in great detail. Opinions differ, even among TFL staff.

http://thefiringline.com/forums/showthread.php?t=430211

cougar - sorry to read about your hearing problems, thanks for posting your experience.

I forgot to put on my hearing protection for 1 round of 10mm, and it was painfully, shockingly loud
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...which is why it's kind of distressing to hear of people using 10mm and Hi-test .357s for home defense.
 
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The problem with measuring impulse noise like gun reports is in the limited bandwidth of the equipment making the measurement.

Most dB meters have a relatively small bandwidth, so a very sharp and fast impulse is NOT measured correctly.

It really takes some more specialized equipment to get reliable readings of impulsive noise.
 
Just shooting 9mm...one time I forgot to put on my headset. I honestly fear ever having to fire a gun inside!!! Just ONE round with my headset off and I was flat out shocked at how loud it was.
 
Tinnitus

Anyone with tinnitus should verify that it is not caused by a tumor.

I went to a ENT doctor in 1993 complaining about tinnitus. He tried decongestants and then suggested piercing my ear drum. I did not have the procedure.

In 2002, I went to the doctor for a sprained knee. I told him about the tinnitus. He referred me to a ENT doctor. He ordered an MRI. The MRI showed an acoustic neuroma, a benign slow growing brain tumor that lies between the acoustic and facial nerves.

I had the tumor treated with Cyberknife, factionated stereotactic radiosurgery. The tumor is dead, but I have constant tinnitus in my left ear. Fortunately, I only notice it when I think about it, like now.

The good news is that I can honestly claim not to hear my wife.
 
Thanks so much for all the help. Very good replies. I never shoot without ear protection but this definitely makes me think twice about buying anything larger than a .45 for personal protection. Once again, really great replies. Thanks so much everyone.
 
Here is the elementary 'math' for decibel calculations : http://en.wikipedia.org/wiki/Decibel

I prefer mass over speed. Keep round subsonic to minimize the noise. Like .45 Colt. or .44Spec. Even with muffs on the 'booooom' of a .45 sounds/feels much better than the 'set teeth on edge' craaaack of a .357. I shot my .44Spec Bulldog without muffs (forgot to put 'em on) under a tin roof 'porch' at the shooting range. It did get the ears to ringing... but it wasn't painful... just unexpected!!!! Oh, it didn't take long for the ringing to go away which was nice and I did put the muffs on immediately :) .
 
The physics of loudness are what they are. However, I also have definite perceptions of relative loudness based on personal experience. I shoot in five calibers: .22 lr, 9mm, .38 special, .357 magnum, and .45 ACP. Of these, the caliber that I perceive to be the loudest is .357 magnum, and among the various weights of .357 rounds, 125gr is the loudest by far. Compared to the others, including .45 ACP, the noise is like night and day. I'm not sure why this is so although I've heard some speculate that the supersonic velocity of .357 rounds is at least partly the culprit. But, they're definitely way louder than anything else, with the possible exception of .44 magnum rounds.
 
cougar - sorry to read about your hearing problems, thanks for posting your experience.
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Thanks for the thoughts!

I am trying to help out the young bucks that feel invincible (as I used to). The silly stuff we do in our youth catches up to us in our old age and the price is FAR higher than anticipated.

One kid I know actually LIKES to shoot without ear muffs, he says it "toughens up" his ears so they can take it. Foolish idiot is what I call him. When cilia breaks it stays broken -- for ever. Try repeating "I couldn't understand you" about 2 dozen times a day and see how that impacts your self perception!
 
Cougar got it right, I have trouble sometimes understanding conversations, especially when there is background noise. And tinnitus is a regular companion now.

Like many others, when I was young I thought I was invincible and didn't think I needed hearing protection. I shot tens of thousands of rounds of .22 without protection, but I think the real damage was the occasional box of .308 or .357 without protection. After those sessions I literally couldn't hear anything more than muffled sound for several days afterward. The last time was with a .357 in a very narrow canyon (rock walls were about 40' apart), and it hurt so much for days afterward that I finally broke down and got some hearing protection. But the damage had already been done.

Couple that with years of loud music, and you get the picture. There is no excuse not to wear hearing protection when shooting. It is not macho to have to ask people to repeat themselves, or pretend that I understood what they said.
 
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