# Sound Pressure Questions **URL:** \ **Category:** Factual Questions\ **Created:** [February 23, 2003, 3:38pm UTC](https://boards.straightdope.com/t/sound-pressure-questions/156982 "2003-02-23T15:38:09Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [February 23, 2003, 3:38pm UTC](https://boards.straightdope.com/t/sound-pressure-questions/156982/1 "2003-02-23T15:38:09Z")
Okay, not too long ago, I over heard some half-wit claiming that the _thumpa_, _thumpa_ stereo in his car put out 60,000 dB. He was dead serious about this and seemed honestly to believe it. Now, of course, there’s no way it could be true, but it got me to wondering: A. How the hell could you generate such a sound? and B. What exactly would happen if you _did_ manage to generate such a sound? (Other than you’d immediately be wiped out by the members of Disaster Area for trying to muscle in on their territory.) ---
**Author:** ![3waygeek](https://avatars.discourse-cdn.com/v4/letter/3/e95f7d/32.png) [@3waygeek](https://boards.straightdope.com/u/3waygeek)\ **Post date:** [February 23, 2003, 3:51pm UTC](https://boards.straightdope.com/t/sound-pressure-questions/156982/2 "2003-02-23T15:51:36Z")
Check out the current [News of the Weird](http://www.newsoftheweird.com/archive/index.html) for a description of “dB drag racing”; last year’s winner only reached 177.7 dB. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [February 23, 2003, 3:57pm UTC](https://boards.straightdope.com/t/sound-pressure-questions/156982/3 "2003-02-23T15:57:57Z")
According to my references dB = 20 log (p/p[sub]0[/sub]) where p[sub]0[/sub]=0.02 mPa. 60,000 dB would be 10[sup]3000[/sup]\*0.02mPA = 2x10[sup]2998[/sup] Pa I don’t think even a supernova can generate that pressure. For reference, if were on the surface of a neutron star, the pressure created by a cubic centimeter of neutronium would be about 10[sup]28[/sup] Pa. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [February 23, 2003, 4:00pm UTC](https://boards.straightdope.com/t/sound-pressure-questions/156982/4 "2003-02-23T16:00:10Z")
Oops, that should have been: 10[sup]3000[/sup]\*0.02mPA = 2x10[sup]299 **5** [/sup] Pa ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [February 23, 2003, 4:15pm UTC](https://boards.straightdope.com/t/sound-pressure-questions/156982/5 "2003-02-23T16:15:38Z")
Considering that every 3 dB represents a doubling of sound pressure level, I don’t think anything could come close to generating 60,000 dB. As **scr4** said, that is a hell of a lot of pressure. Incidentally, death can occur at levels of around 200dB, and 160 dB is recognized as the pain threshold level. Maybe the big bang could have approached that kind of pressure level. Any cosmologists care to confirm this? ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [February 23, 2003, 4:16pm UTC](https://boards.straightdope.com/t/sound-pressure-questions/156982/6 "2003-02-23T16:16:25Z")
Decibels is a logarithmic scale. That is an increase of decibels from 20 to 30 is much less than an increase from 30 to 40. So… 10dB is 10x more than 0dB 20dB is 100x more powerful than 0dB 30dB is 1000x more powerful than 0dB Anything above 85 decibels has potential to cause hearing loss in humans with sustained exposure (in this case hours). Anything above 140 decibels can cause immediate hearing loss to some degree. 60,000 decibels? You’re friend is hugely misinformed. I have no idea what it would do to people nearby but I’d wager his car would explode and anyone nearby would be killed. I wonder if our atmosphere could even propogate such a powerful signal. I’m no scientist but I’d think there’d be an upper limit as to how much compression air can handle before becoming ‘saturated’ so to speak. Just a WAG on my part though. > [@](#): > > Near total silence - 0 dB > A whisper - 15 dB > Normal conversation - 60 dB > A lawnmower - 90 dB > A car horn - 110 dB > A rock concert or a jet engine - 120 dB > A gunshot or firecracker - 140 dB > > SOURCE: [http://www.howstuffworks.com/question124.htm](http://www.howstuffworks.com/question124.htm) ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [February 23, 2003, 4:25pm UTC](https://boards.straightdope.com/t/sound-pressure-questions/156982/7 "2003-02-23T16:25:50Z")
> [@](#): > > \*Originally posted by Tuckerfan \* > \*\*B. What exactly would happen if you _did_ manage to generate such a sound? (Other than you’d immediately be wiped out by the members of Disaster Area for trying to muscle in on their territory.) \*\* I don’t have an exact answer for this but check out what 160dB did to someone in the water (the LFA referred to is the Navy’s Low Frequency Active Sonar which presumably can produce aroun 215-230dB in the water making a bunch of environemntal groups very displeased as they expect it to have a negative impact on marine mammals): > [@](#): > > What is the decibel level known to affect humans? > > According to the Navy’s own study, scientists briefly exposed a 32-year-old Navy diver to LFA sonar at a level of 160 decibels – a fraction of the intensity at which the LFA system is designed to operate. After 12 minutes, the diver experienced severe symptoms, including dizziness and drowsiness. After being hospitalized, he relapsed, suffering memory dysfunction and seizure. Two years later he was being treated with anti-depressant and anti-seizure medications. > > SOURCE: [Ocean Futures Online](http://www.oceanfutures.com/jmc/lfa_qanda.html)