> Does CVSD work only for voice, or can it do music? tones?

CVSD works excellently for any sound. I use a now-obsoleted
DSP for sound reproduction. They are hungry little monkeys
though, and as you say it's easy to gobble up memory. I'm in,
or will be in, the same position as you. One of these days I'll
have to implement CVSD without the DSP as I use up the last
of those available. To keep the fidelity I'm used to I don't see
a way around using a lot of external RAM. The system of CVSD
I'm familiar with is 1-bit serial, which may be difficult to compress.
If it were 8-bit parallel there may be some hope

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