170 DB Sound Noise Hazard from ?

[C. Bryant]

I thought a 170 DB rating
would be only measured for a Chrysler
Siren UP CLOSE or a Jet engine
not for ambulance siren , or Rap music
so read and argue on ........

Corrosive Sound perhaps is the Picture of a Long Beach model 5
not the sound ,because its been long disconnected from Edison.

Note Fifth and Eighth Paragraphs in the story

http://www.gazettes.com/spit07192007.html

I will trade the Boom Box for a working Siren System any day !

So what does FEMA , Homeland Security
do this week, Cut Los Angeles Co. matching $
Funds By 10 % , cheated out of C.D. Siren System again

[Jim_Ferer]

Not 170 decibels. I believe that a Thunderbolt is 160 db at the horn face. If the guy wants to make a point that highly amplified music is too loud and can damage your ears, he's right. Just get the facts straight. Why rap is worse than anything else (death metal, perhaps) is more than I know.

The guy has a point but he makes a lot of mistakes in his screed.

[JasonC]

Some of those "decibel drag racing" cars can get above 175dB but the cars are specially designed, and they only play a solid tone. Rap, or death metal isnt worse than any other music its just the fact that type of music is generally played louder, and has more bass. And since bass propagates well, people drawl conclusions to that.

There's no doubt its bad for your ears. Some systems I've seen, if you stick your head hear the subwoofers, you literally get dizzy and your eyes spin. I'm not sure why, but it doesn't hurt your ears all that much. Maybe it has something to do with the lower frequencies?

[Justin]

Maybe it has something to do with the lower frequencies?

I'm only stabbing air blindfolded here, but since we can only hear within a specific range you won't hear some frequencies despite being extremely loud.
Getting technical with physics, technically an explosion will kill you not by the flames and heat, but rather the shock wave that is produced from the explosion (displacement of air, think of an underwater mine exploding), turning internal organs to mush and such.

It's pretty much the same principle here, high pressure yet inaudible sound waves pass right through your body, causing god-knows-what havoc with your molecules; but won't do any catastrophic damage (like some C4 would) because the waves are traveling much slower.

Makes sense since Jim PM'ed me a random fact as the result of a similar thread: The reason why "shooters" and other staff on aircraft carriers wear those helmets is to protect their grey matter from sound pressure being transmitted through their skulls from some F-16 Fighting Falcon taking off.

[JasonC]

Oh yes. In fact, the military is testing out sound weapons, and several have been deployed. I believe one was successfully used to repel pirates from a small cruise liner in east Africa. They work by concentrating a beam of sound through a parabolic dish and making the affected user very sick and disoriented. Above a high dB level, normal hearing protection won't work. It'll just travel though the bone in your skull as Jim and Justin pointed out.

[Justin]

Oh yes. In fact, the military is testing out sound weapons, and several have been deployed.

I love Discovery Channel.

http://video.google.com.au/videoplay?do ... 3985973299

[Jim Z]

Some systems I've seen, if you stick your head hear the subwoofers, you literally get dizzy and your eyes spin. I'm not sure why, but it doesn't hurt your ears all that much. Maybe it has something to do with the lower frequencies?

our hearing is actually most sensitive in the midrange (800Hz-4 or 5 kHz.) High SPLs at those frequencies will do the most noticeable damage, since it affects speech intelligibility.

[StonedChipmunk]

I heard something about that sound frequency sickness - there was an article somewhere that said the military deployed some sort of device that can detect if a diver is close enough to a ship to blow it up (explosives - yes this actually happens, I guess). If someone comes to close, it fires impulses of sound at a frequency designed to cause sickness - which supposedly causes the diver to reconsider his plans.

Oh, and I hate people who think rap isn't music. What is it, then? There is music in rap. Beat, a tune, etc... there's music... what the heck...

As much as I hate rap, too, it makes you look like an arse when you say it can pass 170 db. Of course, I claimed to my dad that a Modulator in Hawaii could reach 600 db... this was when I was 7, didn't know much about sirens back then. Actually thought that there was a spinning disc with holes in it that made the siren sound... wow...