From: "Paul Keinanen" <keinanen@sci.fi>
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: Shrinking sounds - fiasco
Date: Fri, 23 Jun 2000 14:04:52 +0300
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On Fri, 23 Jun 2000 09:56:46 +0200, "Petr Maly" <p.maly@gmc.net>
wrote:

>Hello all
>Yesterday I spent a while with shrinking WAV's in SoundForge and CoolEdit.
>In the original file (da0lf), there is nothing heard by ear, but when the
>file is open in the Gram, the signal trace is clearly visible. I tried to
>shrink to 50% of the previous length as a first step. I could not hear
>anything either. When I opened the new file in the Gram, the signal
>disappeared completely.

Just a check, but what method did you use to shrink these files ?

Any pesky lossy psychoacoustic compression method such as MP3, Musicam
etc. is definitely NOT suitable for compressing such files. The idea
with all the psychoacoustic compression is to remove all the data that
is not going to be _heard_ due to masking by a strong nearby signal or
by wideband noise (as in this case).

If you use some kind of compression, make sure that you are using some
_lossless_ compression method.

Paul OH3LWR