View Full Version : How loud does something have to be to kill someone?
03-12-2001, 05:32 PM
I saw this once on BattleBots, that it took 150 dB to stop the human heart. Is this true? If so, I'm afraid, since I work in a VERY loud job enviroment (I assemble 747 engines).
So is there a fatal decibel level? And if so, is it really 150 dB?
Please tell me. I'm scared.
Hugs n' Kisses
03-12-2001, 06:15 PM
There are any number of ways (poisoning, for instance) to kill someone in total silence.
Fatal decibel level, INDEED.
03-12-2001, 06:16 PM
150 dB seems a little low for fatality, but I'd guess that 240 decibels (http://thunderstone.com/texis/site/demos/gbwr/+6heGlV29xBmeU-7mkeSxwww/record.html) might do it:
The loudest in a laboratory has been 210 decibels, or 400 000 acoustic watts, reported by NASA from a 14.63 m 48 ft steel and concrete test bed for the Saturn V rocket static with 18.3 m 60 ft deep foundations, at Marshall Space Flight Center, Huntsville, AL in October 1965. Holes could be bored in solid material by this means, and the audible range was in excess of 161 km 100 miles.
03-12-2001, 06:17 PM
Oops, I meant 210 decibels in my link ...
03-12-2001, 07:06 PM
Here's a site that might interest you: Noise What You Can't Hear Can Hurt You (http://www-afsc.saia.af.mil/magazine/htdocs/marmag97/mar2002.htm)
220 Inside detonating diesel cylinder
200 300m from Space Shuttle launch
190 10m from detonating land mine
180 (probable eardrum rupture)
160 Shotgun blast at muzzle
150 Jet takeoff at 10m (instant ear damage)
140 Jet takeoff at 30m (protected ear limit)
130 Pneumatic riveter (unprotected ear limit)
120 Rock concert 2m from amplifier (pain threshold)
110 Chainsaw at arm's length
100 Very noisy factory (cumulative ear damage)
90 Boiler room
80 Inside open sports car
70 Busy office/normal speech at 1 m
60 Washing machine/clothes dryer
50 Light traffic
40 Quiet bedroom
30 Quiet countryside
20 Recording studio
10 Normal breathing
0 Threshold of hearing
-10 Too quiet
Sanders & McCormick (1993)
Kantowitz & Sorkin (1983)
And from the same site:
No amount of head-worn ear protection works well above 150 dB.
03-12-2001, 08:40 PM
03-12-2001, 10:13 PM
I wonder what you would die from.
Seems like a high pitched noise would have to be a lot louder than a low tone one.
In my mind a low tone could vibrate you to death but a high tone would have to do something like pierce you.
I know a nuclear physicist, I'll ask him.
03-13-2001, 01:40 AM
My nieghbor is really loud,
I'm thinking of killing her. :p
03-13-2001, 09:46 AM
This thread reminds me of Douglas Adams and Disaster Area (IIRC, might be Disaster Zone), who typically broadcast their concerts from orbit and a single song could change planetary ecosystems...
03-13-2001, 02:15 PM
wouldn't a loud enough sound created a moving front of highly compressed air? That could be dense enough to set up a shock wave in the blood stream and stop your heart, or simply crush the shit out of you (perhaps literally).
03-13-2001, 02:24 PM
I dont know about stopping your heart...but it does seem odd to me that in movies ( yes I know, not the same as reality)the hero will escape an explosion but be so close to it that it flings him several feet in the air. Forget the shrapnel. He stands up and brushes the dirt off his clothes and might be slightly deaf for a moment or two but quickly recovers his hearing. No bloody nose? No burst eardrums that take more than a few minutes to heal?
Is it the force of the blast or the suddenness of the strong blast that does the damage?
03-13-2001, 02:27 PM
Originally posted by beatle
160 Shotgun blast at muzzle
Hopefully, this is BEHIND the muzzle. In front of it, and 160 dB would be enough to kill you.
03-13-2001, 03:25 PM
This site says that the Guinness Book of World Records says that 192 decibels causes internal injuries that could be fatal:
BTW, I hate to ruin the book if you haven't read it, but noise is a cause of death in The Nine Tailors by Sayers.
03-13-2001, 06:25 PM
I saw a science program on TV (so it must be true) describing a guy who was killed by a nearby (less than 10 meters) lightening strike, but had no visible injuries. Eventually doctors decided that the loud noise from the lightening (the thunder) hit his chest while his heart was at a particularly vulnerable point in between heartbeats, and his heart stopped. The same thing can happen to people who are struck in the chest by a baseball or other fast-moving object. It only rarely causes the heart to stop, but there is a small risk, if the heart happens to be at a certain point in its cycle.
CPR and prompt medical attention would probably save such a victim, so this is probably not a reliable way to kill someone with sound.
03-14-2001, 05:03 PM
Thank you. I was wondering. Now I know I can't die at work.....no......wait.....welding accidents, falling equipment, drunk employees, sharp objects, etc.
I hate working on an assembly line.
03-15-2001, 08:30 AM
Here is the resposne I got from my friend:
Waxteeth, (**funny how my friends call me that**)
You are basically right about the sound waves. The frequency (wavelength) will penetrate the body differently for the different wavelengths. For example, ultrasound wavelengths penetrate the body nicely and are used to image internal body parts. Low frequency however doesn't penetrate. Think of it this way. The low frequency waves have a long wavelength (wavelength x frequency = speed of sound). This wavelength is comparable or larger than your body size. Your body sees (or feels) the sound wave as a pressure burst. Think of sitting in front of a big speaker and feeling the base pound out against you. The higher frequency waves have a shorter wavelength and can penetrate the body. How far depends on how your body absorbs or reflects the sound waves. Either the long or the short wavelengths can cause pain, injury or death depending on the amount of energy deposited in your body.
For example, using ultra sound at low intensities, a doctor might image the baby in the womb, at higher power he might break apart kidney stones. Low frequency sound can cause damage too but it is more like feeling a big burst of air pressure. This burst of air pressure is what actually destroys things when a bomb blows up next to something. Most buildings do not take much pressure difference outside to inside before they collapse.
Sound intensity is measure using the audible decibel (different from power decibel) This measures sound on a logarithmic scale. This means every increase of 10 in decibels increases the sound intensity by 10, 50 dB is 10 times more intense then 40dB, 60 dB is 100 times more intense than 40 dB and so on. Interestingly enough, the human ear apparently works on a logarithmic scale also so 50 dB is not 10 times louder than 40 dB. The point of all of this is that the sound level to cause death is somewhere above 150dB. I'm not sure what exactly it is. I have been told that the payload bay of the Space Shuttle during launch can be around 160 to 170 dB (if I remember right) and was told this was a lethal level. There are many things that are loud enough to kill with the Space Shuttle being one of them.
I hope I answered your question. If not let me know and I'll try again.
friend of waxteeth.
03-15-2001, 11:07 AM
Thanks. That answered everything. The equipment at the assembly line only gets up to around 140-150 dB. Very loud. And I gave someone else my earplugs. Grrrrrr.
Ah well, I'll by some tonight.
I'm posting this at work right now.....oh great, coffee break's over. Back to the assembly line.
I envy those who work in cube farms.
03-15-2001, 01:23 PM
Originally posted by Du_Hast
Thanks. That answered everything. The equipment at the assembly line only gets up to around 140-150 dB. Very loud. And I gave someone else my earplugs.
I find it hard to believe that:
a) You are being exposed to this level of noise exposure without an OSHA and/or NIOSH inspector jumping all over your company, and
b) That you are being exposed to this level of noise without strictly mandated hearing protection (i.e. if you don't have hearing protection, you are immediately ordered off of the assembly line).
In fact, I am certain that your company is required to supply you with adequate hearing protection. Also, earplugs alone aren't going to cut it.
When a worker's time-weighted noise exposure exceeds 100 dBA, both earplugs and earmuffs should be worn... Given the real-world performance of hearing protectors [Berger et al. 1996], NIOSH cautions that even double protection is inadequate when TWA exposures exceed 105dBA.
...How much attenuation a hearing protector provides depends on its characteristics and how the worker wears it. The selected hearing protector must be capable of keeping the noise exposure at the ear below 85 dBA.
03-15-2001, 02:55 PM
Robby: I had earplugs, but I gave them to a friend since he forgot his. I just bought new pair at the store, which is good, since I my hearing was temporarly gone for work. Which is also good since Bonnie Tyler was playing at the store I got them at.
The company I work at tries to ensure our safety, but there's only so much they can do.
03-15-2001, 03:04 PM
Originally posted by beatle
120 Rock concert 2m from amplifier (pain threshold)
Ugh. Been there, hated it. Pal, until you've heard amplified bagpipes backed up by pitiful Korn riffs, you don't know the meaning of hell.
This reminds me of last night's Survivor when Rodger voted for Jerri and said,
'Nice Kid...way too loud."
12-29-2014, 10:09 PM
This is the short answer: 240 decibels is what it takes to explode someones head.
Decibels is the measurement of sound. If you know what frequency is, then good. You're gunna have to. If you've used a dog whistle you know that the sound that is making the dog freak out is too high of a frequency for the human ear to handle, therfore you not being able to hear it. Infrasounds are sounds that you can't hear due to the high or low frequency. 125+ decibals can cause perminent or long-term hearing damage. Now, if you don't know an ipod at max volume is 115 deciables (5 more than a chainsaw). Now let me introduce you to LRAD Long Range Acustic Device. This thing can get so loud it can go to 166 dB without breaking a sweat, which is 4 away from sound itself make you breathe faster. One of LRAD's selling points is that you could mount it to a helicopter and go into the air blasting music so people more than 2 miles away would cringe. Time to get to the point. Infrasounds can make your body vibrate and do things you wouldn't think sound was capable of. Objects can only stand so much force of expansion, before it pops. This includes liquid filled organs, such as the head. Sense the head is so insolated it would take 240 decibles to explode someones head, which obviously would kill them. It could take less, so if I were you I would take percausions. Here is a link to a Game Theory episode which goes in depth of sound: https://youtube.com/watch?v=hmiCMZ9uFiQ
12-29-2014, 10:53 PM
LRAD tops out at 162 decibels-The Game Theory dude pulled that "240 decibel" number out of his ass. You might want to read up on how the decibel scale works (http://en.wikipedia.org/wiki/Decibel).
12-30-2014, 07:14 AM
Since the difference between 160 dB and 240 dB is only a factor of 100,000,000 or so, it seems to me we are nitpicking here.
Perhaps exploding the liquid-filled head of a zombie takes 240 dB from a still-secret LRAD the technology for which you are gunna have trouble grasping until you study frequency more.
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