Doug Von Gausig wrote:
> At 05:13 PM 3/10/2003, Walt wrote:
>
>
>>I should probably point out that the sonograms on my frog pages are of
>>the calls passed through a dynamics filter. By adjusting it's cutoff
>>point I can drop out all the quieter background sound from the sonogram
>>making the call stand out clearly and unmodified. And from the soundfile
>>itself, for that matter. It's a useful filter, but tricky to use for
>>listening, easier to use for sonograms.
>
>
> You can get a similar result by turning the energy range down in CoolEdit=
> to 75 dB or so - play with that a bit.
I can do the same thing in Spark XL by setting the endpoints of the dB
range. Matching their color bands to the sound level of interest. It's
actually easier to do that than the dynamics filter I used on the
website sonograms. The website sonograms are many years old now.
The dynamics filter I used for the sonograms is more than a scaling
thing, it's a real filter that can be used to trim parts of the sound
intensity range, or the reverse, intensify them. And other things I
still don't understand. It's useful, for instance when you have done
regular filtering and have a very quiet residual to get rid of.
The problem in applying it as a filter is that a call is a mixture of
intensities, quiet parts hiding under the louder parts. Sometimes
directly under them. So trimming from the quiet end can only be taken so
far or the character of the call changes. And sometimes that won't show
in the sonogram.
>>I really would like to see what can be done with CoolEdit. I've seen a
>>lot of variation in various posted sonograms from it. But I doubt I've
>
>
> It is enormously versatile. I've posted a series to illustrate a few of t=
he
> combinations you can get at
> http://www.naturesongs.com/recordists/spectral1.pdf.
What's the band limit? I normally use 4096 with Spark XL, and wish it
had higher. If I remember right the website ones were also 4096 ones.
Walt
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