In a message dated 06/02/02, mariotti@......... writes:

I
>  experienced this kind of analysis from since April 1999. I used SOX to 
> convert binary raw data in WAV files. You can find a special web page at:
> http://www.infoeq.it/doc12_e.htm
> 
> I and Andrea Cellini coined the term "phonoseismology" and we published an 
> article on an Italian scientific magazine sometimes ago about it.
> 
> The purpose was to catch out precursor signals.
> Something happened, try to listen the quakes on my web site.
> 
> The ideas of Arie to use stereo channel for two different stations located 
> let's say 10km away could VERY interesting to locate the source of an event.
> I suspected that when i started to use sound analysis as precursor research
> method. Unfortunately i have no possibility to monitor two identical 
> station so far.
> I would strongly encourage each of you to do something in this direction i
> firmly believe will bring interesting results.
> My compliments to Arie!
> Cheers
> Mauro
> 
> ----- Original Message -----
> From: Arie Verveer 
> 

> > Hi All, Lately I've been tinkering around with some code that produces
> > report files from PSN or "Seisan" data. A minor part of the program is to
> > convert PSN or "Seisan" input files to audio files. I thought you might
> > be interested in the output.
> >
> > Have a listen to the latest big quakes at:
> >>    http://members.iinet.net.au/~ajbv/Sound/Sound.html
> > Just click on the image you are interested in......
> > It would be rather interesting to have two close seismic stations on the
> left and right audio channel. Stereo.
> >> Cheers
> >> Arie

Hi Arie & Mauro,

       The initial part of the recording, which presumably contains the P 
wave, sounds as if it has a much greater high frequency content than the 
subsequent section. Is this evident from the FFT of the source, when you 
divide it up into two relevant sections? 

       There are two methods of making very low frequency signals audible to 
the human ear in real time, rather than in 'accelerated time'. One method is 
to generate a continuous tone at say 1 KHz and then use a gain control chip 
to control the output amplitude. The other way is to use the signal to 
control the frequency of a Voltage / Frequency converter. It might have an 
output frequency of 1 KHz with zero input and be modulated by the signal 
around this value. 

       Do you know if either of these methods have been tried out and if they 
have provided useful information, either listening to them directly or from a 
recording?

       Regards,

       Chris Chapman
In a message dated 06/02/02, mariotti@......... writes:



I

 exper
ienced this kind of analysis from since April 1999. I used SOX to convert binary raw data in WAV files. You can find a special 
web page at:

http://www.infoeq.it/doc12_e.htm



I and Andrea Cellini coined the term "phonoseismology" and we published an article on an Italian scientific magazine someti
mes ago about it.



The purpose was to catch out precursor signals.

Something happened, try to listen the quakes on my web site.



The ideas of Arie to use stereo channel for two different stations located let's say 10km away could VERY interesting to lo
cate the source of an event.

I suspected that when i started to use sound analysis as precursor research

method. Unfortunately i have no possibility to monitor two identical station so far.

I would strongly encourage each of you to do something in this direction i

firmly believe will bring interesting results.

My compliments to Arie!

Cheers

Mauro



----- Original Message -----

From: Arie Verveer <ajbv@............>

Subject: Sound Files



> H
i All, Lately I've been tinkering around with some code that produces

> report files from PSN or "Seisan" data. A minor part of the program is to

> convert PSN or "Seisan" input files to audio files. I thought you might

> be interested in the output.

>

> Have a listen to the latest big quakes at:

>>    http://members.iinet.net.au/~ajbv/Sound/Sound.html

> Just click on the image you are interested in......

> It would be rather interesting to have two close seismic stations on the

left and right audio channel. Stereo.

>> Cheers

>> Arie




Hi Arie & Mauro,



       The initial part of the recording, which presumably contains the P wave, sounds as if 
it has a much greater high frequency content than the subsequent section. Is this evident from the FFT of the source, when you 
divide it up into two relevant sections? 



       There are two methods of making very low frequency signals audible to the human ear in
 real time, rather than in 'accelerated time'. One method is to generate a continuous tone at say 1 KHz and then use a gain con
trol chip to control the output amplitude. The other way is to use the signal to control the frequency of a Voltage / Frequency
 converter. It might have an output frequency of 1 KHz with zero input and be modulated by the signal around this value. 



       Do you know if either of these methods have been tried out and if they have provided u
seful information, either listening to them directly or from a recording?



       Regards,



       Chris Chapman