Hi Petra: Very informative.

I've a few more Q's if u don't mind....

"Let me use the Nisqually quake for an example. The length of the sound was 15 seconds, but it was really loud, so I knew this quake was going to be extremely large. It also had a very unusual tone, one that I had never heard before. The original tone was heard and then at the end it sounded like the tone was spreading out in a circular way. Imagine a typical epicenter circle and the sound traveled outward."

+ Could you download and install the sweep frequency tone generator and find/set the settings which most closely matched what you heard (assuming you can remember it that well ...since it was awhile ago....)?

"The tones travel at 37/38 miles per second. IE: if a 3 second tone arrives the epicenter will be between 111 and 114 miles away."

+ How many data points were used to come up with this approximation?
+ How do you discriminate between a 3 second tone that is say 1000 miles away and 100 miles away ? Do you use "loudness" to discriminate?

"Yes. Each area has its own geology and from knowing the geologic structure, then you know where the sound eminates. Very solid rock such as granite produces a very high pitched sound, area's more dense in soil are muffled, volcanic area's sound like the basic sound with a fuzziness around the edge of the sound. Off shore can sound like one has their head under water."

+ Very good....
+ BTW, do you know of a (geology) map that shows where quartz crystals are found underground ?

"It took me two years to explain to Don over and over again that I did not have tenitus, but heard a single sound and it came and left in a short period of time"

+ Yes...I think tenitus is a steady state condition whereas the "tones" are short duration....

"Its always a lesson inside of a lesson"
+Yes...I'm finding that when I survey a topic (to "close it out") there's always yet another "lesson" in the subject to be learned....

Good Post.

2cents

• Test Tone Generator (allows frequency sweep)