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Re: SNAP versus BOOM

At 22:20 7/5/01 -0400, John Denker wrote:

Have you ever noticed that fireworks up close go SNAP SNAP-SNAP,
while fireworks far away go BOOM BOOM-BOOM?

The timbre of the sound is markedly different different.

A friend of mine remarked on this and asked Why?
Is there any good physics in this?


This URL offers the attenuation vs frequency and humidity table
shown beneath:

<http://www.epanorama.net/documents/audio/attenuation_data.html>


----- dB/ft loss vs humidity @ 20 deg C (68 deg F) -----
frequency 0% 5% 10% 20% 40% 60% 80% 100%
=====================================================================
100 Hz 0.0005 0.0002 0.00016 0.00016 0.00013 0.0001 0.00008 0.00007
1 kHz 0.0007 0.006 0.0035 0.0015 0.0009 0.001 0.0011 0.0012
4 kHz 0.0027 0.023 0.031 0.027 0.0085 0.0057 0.0046 0.0041
10 kHz 0.008 0.031 0.061 0.080 0.047 0.031 0.023 0.019
20 kHz 0.023 0.049 0.086 0.172 0.155 0.114 0.088 0.072
40 kHz 0.081 0.116 0.152 0.250 0.380 0.364 0.313 0.270
80 kHz 0.315 0.367 0.404 0.508 0.754 0.900 0.926 0.888
------------------------------------------------------------------------




brian whatcott <inet@intellisys.net> Altus OK
Eureka!