Re: [Audacity-nyquist] Echo Location

[paul b. <sni...@fa...>]

Hello Sami, 

You used the term color. Light travels at different velocities in a
medium such as glass or water. This is why the colors appear as red,
green, blue, ect. in a prism or rainbow. 
That is, blue travels a little faster than red. This is not true in
outer space, all frequencies travel at the same speed in a vacum. 

David Sky wrote a plug-in for wind noises; I can't say if it is relevent
to this discusion, but the wind, sonar, and a bit of Das Boot are here,
it takes about 30 seconds for dial-up to load this MP3,

http://www.proviewlandscape.com/prop/the_sub.mp3

enjoy--Paul 
 
 


On Mon, 1 Oct 2007 15:36:52 +0300, "Sami Jumppanen"
<sam...@gm...> said:
> Hello,
> 
> I need to say a few things about the audio spectrum of lightning:
> 
> On 27/09/2007, paul beach <sni...@fa...> wrote:
> > Frequencies do not travel at the same velocity. With a lightning strike,
> > at a distance, a rumble follows the initial crack. I don't know if dispersion is possible.
> 
> 
> I've thought about how to synthesize lightning strikes (the audio),
> and I've needed to understand the principles on how the sound is
> formed, what is behind the "colour" of the sound. I don't understand
> everything yet, dispersion is one of those things.
> 
> The initial cracking sound is heard due to a few things:
> 
> 1. It is from a branch (inside the cloud) of the main discharge
> channel. The weakness of the discharge branch leads to higher pitched
> sound.
> 
> 2. The branch is close to the observer. Even if the branch is weaker,
> it is close enough to be heard well. You can't usually see the branch
> because the flash intensity is too low to shine through the cloud.
> 
> 3. The branch is aligned lengthwise - not vertically, in the point of
> view of the observer. If the branch produces low frequency audio, it's
> not emitted towards the observer.
> 
> This is based on my own observations and thoughts. There is a lot more
> things to take into account when generating the correct sound, like
> how sound travels in moist air and through the thick clouds, and how
> the shockwave effect varies depending on the observer distance and
> intensity of the lightning strike. If someone is going to develop a
> thunder audio generator, I'd be happy to throw in my few ideas.
> 
> -- 
> Sami "Some-E" Jumppanen
> sam...@gm...
> http://netti.nic.fi/~some-e/
> 
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-- 
  paul beach
  sni...@fa...