[WebHobbit]

Does anyone remember a gun magazine article from a few years back where they measured decible levels of various handgun defensive loads? The article was about what (if any) hearing damage/loss was likely to occur if one should have to actually EMPLOY a handgun indoors for self-defense sans ear-muffs/plugs.

I THINK the results were pretty similar across the board from .38-.44 Magnum. It did vary 10-20 DB but all of 'em were enough to cause atleast temporary & sometimes permanent loss of some hearing. I'm not totally sure as this is from memory. :scrutiny:

It was probably in either Handguns or Combat Handguns but I'm not sure. I used to have several HUNDRED gun magazines but I finally got rid of the vast majority of them. Guess I should have kept them!

Anyone still have this mag? Anyone remember the article? Someone mentioned using .38+p in a 686 rather than .357 for home-defense because they were concerned about hearing damage in another thread and that got me thinking back to that article.

[JohnKSa]

The only way that kind of reasoning makes sense is if you can limit the attackers choice of calibers too...

Pick what does the job and what you're comfortable with. They'll all damage your hearing indoors. Even a .22

[Double Naught Spy]

I do not know the particular article you are interested in, but here is an example of similar data.

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

That said, however, sound pressure (db levels) does not rely simply on caliber. Consider these attributes:

Sound pressure is directional
Proximity to the sound source
Sound source characteristics
Intensity of the sound pressure
Duration of the sound pressure
For most guns, the majority of the sound pressure is broadcast from the muzzle and in the direction the gun is pointed.

What this all comes to is that many factors come into play. For example, shooting my AR isn't too bad, but for anyone to either side of me, they are going to experience the pressure much more.

What makes indoor shooting so significant to the problem is the reflected pressure. Unlike outdoors where you might experience the pressure only a couple times per shot (actual firing sound, then sound reflected back up from the ground, inside you may get hit numerous times as the sound bounces off the floor, walls, and ceilings. That this means is that the duration of the event is prolonged.

Probably as a realistic consideration, if you are using normal loads and do not have a silenced gun (and even then it might not be enough), virtually no firearms are safe to fire indoors and without hearing protection. If the protection is not adequate, then some damage may still occur.
For more about hearing loss and guns, see ...
http://keepandbeararms.com/information/XcIBViewItem.asp?ID=2052

[WebHobbit]

Thanks! This is what I'm talking about:



Table 3. CENTERFIRE PISTOL DATA

.25 ACP 155.0 dB
.32 LONG 152.4 dB
.32 ACP 153.5 dB
.380 157.7 dB
9mm 159.8 dB
.38 S&W 153.5 dB
.38 Spl 156.3 dB
.357 Magnum 164.3 dB
.41 Magnum 163.2 dB
.44 Spl 155.9 dB
.45 ACP 157.0 dB
.45 COLT 154.7 dB



This nicely proves my theory that a .357 indoors isn't really any worse on your hearing than a .38. Now if I could find the THR thread wher the guy says that! ;)

[Southern Raider]

This nicely proves my theory that a .357 indoors isn't really any worse on your hearing than a .38.
dB is a logrithmic measurement much as the Richter scale is for earthquakes. It's not linear. Each 10dB represent 10 times the energy hitting your ears. In other words, the roughly 8dB difference between a 357 and a 38 represents 6.3 times the energy hitting your ears.

[Island Beretta]

In a SD situation your auditory perception will worsen.. so hearing loss would not be a worry for you then and should not.. you probably will hear the first shot clearly and thereafter the shots sound muffled.

The real threat to your hearing loss is at the range or when training and quite a few ROs do not hear so well!! :cool:

[themic]

southern raider is right about the dB scale, except that the rule is
a factor of 10 in amplitude increase corresponds to a 20 dB boost (increase by 20 dB). so a 357 is roughly 2.5 times the sound level of a 38. which is still a lot.

also don't forget that different frequencies (pitches) affect our ears diferently. this will dependon the caliber, brand, and even type of gun you're shooting. there's no general rule for which gun/ammo combos produce which tones (and they all produce a variety of tones), and which tones will hurt your ears the most.

sometimes i think the larger calibers/lower speeds are lower deeper tones, but i can't really tell without taking my ears off.

my thought has always been: avoid the recoil control barrels with the hole in them, and if you know you're going to shoot indoors, you may want to avoid the magnum calibers. that's about the best you can predict.

or get yourself a sound suppressor if you're really worried. they're legal in some places.

[themic]

dB info:
http://www-ccrma.stanford.edu/~jos/mdft/Properties_DB_Scales.html

[themic]

a better link for decibels:
http://analyst.gsfc.nasa.gov/FEMCI/random/dB.html

[themic]

ok my bad. since sound levels are done in terms of power or intensity, it's actually 10Log not 20Log.

old electrical classes... 20Log is for voltages, 10Log is for Power. :banghead:

http://www.sospubs.co.uk/sos/1994_articles/feb94/decibels.html

[El Tejon]

web, it depends. Maybe the crackenflasher will be worse, maybe not. Lots of factors at play in the world o' science.

I would be more concerned about flash, especially from the gunzine loads. YMMV. Test them out--FOR SCIENCE.:D

[Double Naught Spy]

I think some of y'all may have missed a serious point concerning decibels. Sure enough, loudness doubles with ever 10 db increase, but the loudness is not the issue. It is the pressure.


I really liked this comment from the link I posted above to give a rough, non egghead empirical perspective...
"In other words, 1 bullet equals 1 week of hazardous occupational noise exposure. An avid target shooter can be exposed to an entire year's worth of hazardous occupational noise in just a few minutes."

Another way of looking at it that is quite simple to understand is that for every 3 db increase, there is a doubling of the power or pressure. So why 3 db does not actually sound that much louder, it is impacted with twice the force on the mechanical parts of the ear. See the site I posted above and look at the figures. It really is a good article and puts things into perspective nicely.

[WebHobbit]

Guys, I KNOW .357 is louder than .38 but what I'm saying is they can BOTH potentially hurt your hearing. My point is .38 isn't quiet enough to be "safe" therefore you may as well go with what is more effective ballistically - with all other items being equal.

[ElAlumno]

Both my shootings were indoors.

First was a .357 mag 125 gr.

Second was two 20 ga. No. 4 birdshot and 4 9mm 115gr STHP

In neither case did I notice the noise or was I affected afterwards.

[bountyhunter]

"southern raider is right about the dB scale, except that the rule is a factor of 10 in amplitude increase corresponds to a 20 dB boost (increase by 20 dB)."

If the unit in question is acoustic POWER, then a 10X increase in power is given by a 10dB increase, a doubling in power corresponds to a 3dB increase. As far as perceived loudness, a good rule of thumb is that when a sound appears about twice as loud to a listener, that is generally about a 10dB increase.

As to the question of dBA levels and hearing damage: anything about about 110 -120 dB is very dangerous. Above 130 gets into levels which cause permanent damage. A point to remember is that indoors, most of the sound hitting your ears is reflected so the "damage level" goes up considerably compared to an outdoor shooting exposure. BTW: if you are at an indoor range anywhere near a .357, .44 mag, or .50, your hearing is being destroyed regardless of your ear plugs and muffs.

[Bowlcut]

saturday i was caught off guard with my muffs up talking at the indoor range. not sure what the one other guy at the range not in our group was shooting, either 9 or 45.... but it hurt. rung my ears well. he was maybe 10 yards away at the very most. my ears rang and buzzed till today when ive noticed it isnt there...or ive just not been quiet long enough to notice.

something i wont do again....eletronic muffs here i come

[triggertime]

What you're thinking of can be found in the May 1994 issue of 'Handguns' magazine. The article was entitled "Muzzle Blast And Your Hearing" by Ed Sanow.

As usual, Sanow's data was inconsistent. The comparison table that ended up being published was taken from data acquired from firing various calibers on an open range, not from firing them from inside an enclosed space.

According to Sanow's table, we find that a .38 Special +P averaged 117dB when fired outdoors. But to find how loud it was when fired indoors, you have to skim the article.

Sanow writes, "The same .38 Special +P load that produced 117dB in an open range generated 131dB when discharged inside a bedroom. This 25-times increase in energy is the same as shooting a .357 Magnum in an open field. The same .38 Special +P load fired inside a car produced 137dB."

A 14dB increase in loudness is a 25-times increase in energy? Whatever, Sanow. :rolleyes:

[jc2]

In a SD situation your auditory perception will worsen.. so hearing loss would not be a worry for you then and should not.. you probably will hear the first shot clearly and thereafter the shots sound muffled.
Not necessarily true. Your auditory (and visual) perception does not necessarily change--it might or it might not (and it could vary from time to the next). There is no guarantee you will be able to continue to function after squeezing off one round in 125-grain SJHP in an enclosed place (e. g. maybe from a SP101 in the cab or your pick-up truck).

Even if your mind does trick you, and you don't hear the shot(s), the damage will be there--it has absolutely nothing to do with the perception of the noise. While you may rightly say, it is a better to be alive and deaf, you really don't have to make that choice (between being deaf or being alive). The good thing is that what with today's ammunition we do not depend on rounds with a huge muzzle blast like the .357 Magnum or 357 Sig for effective ammunition. You can achieve the same effectiveness with considerably less muzzle blast by careful ammuniton selection (and save your hearing--or at least some of it). There is really no excuse to use those loud blasters with the quality ammunition available to us today.

[JohnKSa]

Auditory exclusion is a mental phenomenon. Your brain isn't registering the information because it's too busy trying to save your life. The same sound pressure hits your eardrum, and the damage to the ear is the same regardless of whether you "heard" the sound or not.

A single firearm shot indoors will permanently damage your hearing if you aren't wearing protection. Hearing damage, in the beginning, isn't generally detectable without a medical test unless the loss is severe. Usually, it is undetected (without special testing) until later in life. As people age, hearing function decreases. Those with hearing damage experience a more rapid and severe decrease than a person without hearing damage.

Furthermore, hearing loss is cumulative--just because you already have damage doesn't mean you can't get more.

I've posted this before, but here goes again. Any temporary deafness or ringing in the ears is considered to be evidence that permanent hearing damage has taken place. The fact that the deafness "wears off" or the ringing subsides doesn't mean anything. The threshold of pain is above the threshold of damage. The fact that a loud sound didn't hurt your ears is NOT evidence that no hearing damage took place.

One other thought. Most hearing protection reduces the sound y approximately 30dB. If you look at the figures you will see that most of the figures are high enough that a 30dB reduction isn't going to reduce the sound to safe levels--especially not for an extended indoor shooting sessions. It's a good idea to double up--use plugs and muffs.

Ok, let's be real--hearing is precious, but not as precious as life. When the bullets start flying in earnest, the noise they make should be the least of your worries.

[WebHobbit]

Thanks triggertime! That was it! I knew someone must have read it here!



BountyHunter said:

BTW: if you are at an indoor range anywhere near a .357, .44 mag, or .50, your hearing is being destroyed regardless of your ear plugs and muffs.

I don't know if I buy this. I've shot my .357 at the indoor range many times & I don't think I've taken any damage. No, I have not been tested but I've never had any pain , discomfort or ringing. This was with muffs only. I may add plugs as well after this thread!

[WebHobbit]

Both my shootings were indoors.

First was a .357 mag 125 gr.

Second was two 20 ga. No. 4 birdshot and 4 9mm 115gr STHP

In neither case did I notice the noise or was I affected afterwards.





:eek:

ElAlumno! Details, details! How close were you, etc., etc. Were you firing or what?

[valnar]

Webhobbit.
I may be a little late to this thread, but it was me who posted the original question about the .38sp+P vs .357Mag indoors. Thanks for this follow up discussion.

It turns out we're screwed no matter what - indoors!

Robert

[Southern Raider]

A 14dB increase in loudness is a 25-times increase in energy? Whatever, Sanow.
TriggerTime,
Detention for you young man for not paying attention to the engineering lecture earlier in the thread! ;)

A 14dB increase in loudness is indeed a 25 times increase in energy. (25.119 to be exact at 3 decimal places). Remember, every 10dB increase is 10 times the energy. 10dB is 10 times, 20dB is 100 times, 30dB is 1000 times, etc.

In other words, power increase = 10 raised to the (dB increase / 10) power. In the example given, 10 raised to the 1.4 power is 25.119.

Even Sanow gets something right every once in a while. :what:

[ElAlumno]

Web,

First shooting was at a domestic in which I was the backup officer. While trying to cool things down and resolve the incident the man broke away and went to the kitchen and grabbed a knife. Due to the timing and proximity I felt I had no choice but to shoot. At the time I carried a S&W Mod 65 with 125gr. SJHP. I fired one round. After the shooting I felt no ill effects from the noise of the discharge of my weapon.

Second shooting was serving an arrest warrant on a violent felon. When we entered the home he opened up with two rounds from a 20 ga. I responded with four rounds from my handgun as I was ducking. (We carried the 115gr. STHP.) I then pulled my partner out and we called SWAT. Once again, the noise from the discharge of the weapons was not a perceived factor. I was much more concerned with other things.

Now, was there some sort of damage done to my hearing? I don’t know. I can’t imagine that firing guns indoors like that is a healthy thing. Yet, with the stress of the shooting and all the other concerns I didn’t really feel that the discharges were loud. Stress seems to do a lot to a body.

[triggertime]

You said:

"dB is a logrithmic measurement much as the Richter scale is for earthquakes. It's not linear. Each 10dB represent 10 times the energy hitting your ears. In other words, the roughly 8dB difference between a 357 and a 38 represents 6.3 times the energy hitting your ears."

Detention for me? In Sanow's article he notes that he used a Quest Model 215 Sound Level Meter set to the linear or unfiltered scale.

You've stated that dB is a logrithmic measurement that is not linear and that each 10dB increment represents 10 times the energy hitting your ears.

From what I've cited from t

[triggertime]

You said:

"dB is a logrithmic measurement much as the Richter scale is for earthquakes. It's not linear. Each 10dB represent 10 times the energy hitting your ears. In other words, the roughly 8dB difference between a 357 and a 38 represents 6.3 times the energy hitting your ears."

Detention for me? In Sanow's article he notes that he used a Quest Model 215 Sound Level Meter set to the linear or unfiltered scale.

You've stated that dB is a logrithmic measurement that is not linear and that each 10dB increment represents 10 times the energy hitting your ears.

From what I've cited from the example in Sanow's article, the difference between 117dB and 131dB is 14dB. How is 14dB a 25 times increase if you've stated that 10db only represents a 10 times increase?

Instead of sending me to detention for supposedly not paying attention, perhaps you should be sent there instead for being contradictory in your explanations.

Here's an idea, take Sanow with you so both of you can play a little paper football to pass the time. :p

[Southern Raider]

TriggerTime,
I'm sorry, but I cannot change the engineering analysis and math behind all this. It is widely accepted and confirmed. I also fail to see where I have been contradictory in my explanation. Each 10dB increase is a 10 times increase in power. (10dB is 10 times, 20dB is 100 times) What is perhaps confusing you is that a linear progression in decibels represents a geometric progression in power levels. In other words, addition in a logrithmic scale is the same as multiplying in corresponding linear scale.

I don't know what the Quest Model 215 Sound Level Meter set linear or unfiltered scale entails, but decibel measurements are logrithmic. That is how they are defined.

If you want the answer as to why a 14dB increase represents a 25 times increase in power, look at my previous post for the math, or

power increase = 10 raised to the (dB increase / 10) power

For the example, 10 raised to the 1.4 power = 25. Get a calculator and check it yourself. You can also check that 10 raised to the 1 power is 10 and 10 raised to the 2 power is 100. (i.e. 10dB is 10 times greater and 20dB is 100 times greater)

Or we can do it as you seem comfortable. The first 10dB represents 10 times the power. Four more dB represent approx. 2.5 times the power. Since adding algorithms represents multiplication in the scalar domain, 10 * 2.5 = 25.

Don't forget to clear the erasers in detention hall...:D

[Double Naught Spy]

Y'all can argue all the physics semantics all you want. Most of that is out of my league. No matter how you do the math, there is not any normal caliber and unsilenced firearm that is auditorily safe to fire indoors w/o hearing protection such as might be done in a self defense shooting.

And JohnKSa and jc2 are absolutely right about auditory exclusion. Just because you didn't hear the shot (mentally) does not mean that you didn't suffer the effects of the over pressure. This is a mechanical issue. Once again, take a look at the like I posted above. Included there are pictures of the mechanical damage that can result from experiencing sounds that are too loud.

Also once again, the loudness of the gun or caliber is not the only salient issue here. There is a definite directional aspect as well. In shooting outside with little reflected sound, shooting my AR is not unpleasant at all as I am directly behind the muzzle that is pointed away from me. Five feet to my left or right and the experience is not so pleasant for a person in those locations. Being slightly down range and a few feet to either side is a lot worse. Of course, some guns project sound more directionally than others.

[bountyhunter]

"Detention for me? In Sanow's article he notes that he used a Quest Model 215 Sound Level Meter set to the linear or unfiltered scale.

You've stated that dB is a logrithmic measurement that is not linear and that each 10dB increment represents 10 times the energy hitting your ears. "

dB's are definitely logarithmic excatly as described in the threads. The "linear" herring thrown in is also correct, but has nothing to do with dB's:

All acoustic meters have different "scales" which adjust how the microphone's frequency response is dialed in to the meter. The "linear" scale (commonly called the "C weight") means all frequencies are given equal loudness so the response of the input stage is linear (flat) with frequency, hence the statement it is the "unfiltered" scale.

The human ear's frequency responce is extremely non-linear, and drops off tremnedously at lower frequencies. Most acoustic meters ahve another scale that mimics the ear's frequency response (the "A weighted") scale, which is actually more indicative of how loud a sound will hear to a person. The sound input to the meter is fed through filters to approximate the ear's characteristics.

[bountyhunter]

"Also once again, the loudness of the gun or caliber is not the only salient issue here. There is a definite directional aspect as well. In shooting outside with little reflected sound, shooting my AR is not unpleasant at all as I am directly behind the muzzle that is pointed away from me. "

YES! And, at an indor range, the sucker in the lane next to the magnum is getting blasted worse than the shooter because there is a bit of a null (dropoff) directly behind the muzzle. Still loud, not as loud as the poor schmuck in the next lane hears.

[JohnKSa]

the sucker in the lane next to the magnum is getting blasted worse than the shooter because there is a bit of a null (dropoff) directly behind the muzzle.
True--unfortunately the null is small (spatially, that is.) So small that shooters tend to lose their hearing in their weak-side ear first because it is farther off the bore axis than the strong-side ear.

[cratz2]

From listening to car stereos, 10dB is a big damn difference! 120 dB is a loud but comfortable listening level, 130 dB you are going to have a hard time talking over it, 140 dB and the guy one block down can hear the bass.

I also know the difference between shooting 124 Gr +P out of my Kahr with a 3.5" barrel is a world of difference louder than shooting 230 Gr SP or +P out of a 5" 45ACP. Now I'm sure a lot of that has to do with supersonic vs. subsonic and being behind the gun (which is hopefully where you will be) may mean there's a bigger difference in actual shooting.

Inside the house, I have no clue but just shooting outside, the 45ACP is much more quiet than the 9mm.