MSheldon Posted July 14, 2016 Report Share Posted July 14, 2016 Hi All, I ran across this article this morning and thought some of you might enjoy it. The article goes a little deeper into the subject than the title might imply. http://fivethirtyeight.com/features/the-loudest-sound-in-the-world-would-kill-you-on-the-spot/ Cheers, Matt Quote Link to comment Share on other sites More sharing options...
Wandering Ear Posted July 14, 2016 Report Share Posted July 14, 2016 Cool article. Thanks for sharing. Guess I should be prepared to "hold for volcano" Quote Link to comment Share on other sites More sharing options...
ryanpeds Posted July 19, 2016 Report Share Posted July 19, 2016 I did some work with Orbital ATK that is building the new rockets for NASA and it is even louder than the Saturn V rocket. Quote Link to comment Share on other sites More sharing options...
ramallo Posted July 19, 2016 Report Share Posted July 19, 2016 The loudest sound (SPL) in the air is equal to 1 ATM at sea level 1ATM=101325N/m2 ---- 20x log(101325/0,00002)= 194dB SPL (Sound Pressure) (Propagation thru the air) Sound pressures over 1ATM are truncated. The Nasa article talks about Power (The power of the source) http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120003777.pdf The article mix sound pressure and sound power. Quote Link to comment Share on other sites More sharing options...
Izen Ears Posted August 8, 2016 Report Share Posted August 8, 2016 Wow awesome read thanks!! Mr. Ramallo - that is some crazy numbers thing you've got going on there. Care to explain? What the hell is an ATM?! Why would over 1 ATM be truncated? This thread went way over my head! Dan Izen Quote Link to comment Share on other sites More sharing options...
Simon Hayter Posted August 8, 2016 Report Share Posted August 8, 2016 I think ATM is atmospheric pressure. Quote Link to comment Share on other sites More sharing options...
Constantin Posted August 8, 2016 Report Share Posted August 8, 2016 The article mix sound pressure and sound power. I can't open the article at the moment anymore, but I remember from reading it a while ago, that the article did use both sound pressure and sound power, but they didn't mix it. They explained the different usages in the first chapter. IIRC sound power referred to sound directly at the rocket, and sound pressure referred to sound further away. Of course, this discussion would be a lot easier if the article were still there. Quote Link to comment Share on other sites More sharing options...
ramallo Posted August 8, 2016 Report Share Posted August 8, 2016 Mix pressure and power on the graphics (For example the rocket dB is power not SPL) 7 hours ago, Izen Ears said: Wow awesome read thanks!! Mr. Ramallo - that is some crazy numbers thing you've got going on there. Care to explain? What the hell is an ATM?! Why would over 1 ATM be truncated? This thread went way over my head! Dan Izen ATM is Atmospheric pressure, at sea level 1ATM is the pressure (It depends) Quote Link to comment Share on other sites More sharing options...
Marc Wielage Posted August 9, 2016 Report Share Posted August 9, 2016 I was only about 2 miles away at the press site from Apollo 17 when that took off in December 1972, and I can testify that a Saturn V is damned loud. Quote Link to comment Share on other sites More sharing options...
Constantin Posted August 10, 2016 Report Share Posted August 10, 2016 Mix pressure and power on the graphics (For example the rocket dB is power not SPL) Yes, but that's exactly what I said. They do not mix those two terms indiscriminately. In the paragraph labelled "Overview" they explain why they sometimes use "sound power" (the acoustic power at the engine) and "sound pressure" (propagation of acoustic energy). What is wrong with this? Or where did they get this wrong? Quote Link to comment Share on other sites More sharing options...
ramallo Posted August 10, 2016 Report Share Posted August 10, 2016 The sound power are inherent to the source (Always is the same not depends of the distance for example), but this power have the need of a medium for propagation (F.E. air). IMMO The "loudest sound" is always related to "pressure" The loudest sound (Pressure) in air is 194dB SPL peak at sea level (1ATM) Apples with apples and oranges with oranges. IMMO Is wrong mix both, and is easy get a estimated pressure from power (uninformed redactor?) You can see a right table on the Wiki (oranges with oranges) https://en.wikipedia.org/wiki/Sound_pressure Quote Link to comment Share on other sites More sharing options...
Constantin Posted August 11, 2016 Report Share Posted August 11, 2016 Apples with apples and oranges with oranges. IMMO Is wrong mix both, and is easy get a estimated pressure from power (uninformed redactor?) Well, that may be your opinion, but it's not the opinion of the scientists at NASA. It's not an uninformed redactor, rather - again - they do explain why and when they use power and pressure and then they use both in this article (and elsewhere on the NASA site), but they use each term in its right place as defined in the article. Here is another orange for youhttps://en.m.wikipedia.org/wiki/Sound_power(Although that article is not very well written) Quote Link to comment Share on other sites More sharing options...
ramallo Posted August 15, 2016 Report Share Posted August 15, 2016 On 11 de agosto de 2016 at 7:39 PM, Constantin said: Well, that may be your opinion, but it's not the opinion of the scientists at NASA. It's not an uninformed redactor, rather - again - they do explain why and when they use power and pressure and then they use both in this article (and elsewhere on the NASA site), but they use each term in its right place as defined in the article. Here is another orange for youhttps://en.m.wikipedia.org/wiki/Sound_power (Although that article is not very well written) I said "uninformed redactor", is my opinion, sorry. Isn't possible mix Sound Pressure and Sound Power in this table (In the same axis) Thank you for the wiki page (is the same as I wrote), I recommend you read carefully as well https://en.wikipedia.org/wiki/Sound_pressure Thank you! Quote Link to comment Share on other sites More sharing options...
Scott Anderson Posted August 20, 2016 Report Share Posted August 20, 2016 Enjoyed reading that thanks for the link. Quote Link to comment Share on other sites More sharing options...
JonMoore Posted September 27, 2016 Report Share Posted September 27, 2016 Nice article. They point out human hearing is 64-23k Hz. Have I been living a lie of 20-20k? The pistol shrimp is the loudest animal in the world. It snaps its claw to stun its prey; hitting up to 200dB! I'm assuming underwater sounds would be weighted differently than sounds propagating in our air due to the fact it's harder to hit high dB ratings in a gas. Quote Link to comment Share on other sites More sharing options...
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