[sdiy] vocoder filters
colindorward at gmail.com
Sun Sep 1 07:21:29 CEST 2019
I think maybe this has branched off from it's parent thread now, so I will
respond here. Thanks for the replies!
Take a look at speech CODECs like linear predictive coding, CELP, SPEEX,
A variant of this digital "vocoder" is used in the GSM baseband processing
that conveys speech over mobile phone networks with minimal bitrate
Oh I never correlated vocoding so directly with the telecom industry, but
of course it makes perfect sense that's where the tech would be developed.
Also check out Ray Wilson’s take with a very detailed writeup:
Am I missing something? Ray Wilson's looks like fixed frequency BPFs.
If applied to music, probably one thinks of synthesizing singing or some
DESIRABLE vocal effect. I tried this:
Inspiring read! I think I'll build that sawtooth phase shifter.
On Sat, Aug 31, 2019 at 7:25 PM Bernard Arthur Hutchins, Jr <
bah13 at cornell.edu> wrote:
> Of courses vocoders have “dynamic poles” (not fixed resonances) – else
> what is the point? In the original application (Voice-Coder) the idea
> was to exploit the redundancy in human speech (10:1 to 50:1 - - said
> redundancy being the repetition of many very similar “cycles” in time that
> constitute a particular vowel/phoneme/syllable). Instead as few as three
> bandpass resonances might well represent a “frame” of 1/5 a second. A
> loss of quality of stored/transmitted speech for a vast reduction of memory
> required (expensive in the early days). But clearly the resonant
> frequencies changed with each new frame encoded.
> If applied to music, probably one thinks of synthesizing singing or some
> DESIRABLE vocal effect. I tried this:
> The “animator” worked through a series of (LFO controlled – see Fig. 7) of
> POSSIBLE formant frequencies (phonemes both used and unused in a particular
> language). It worked - it sounded human! BUT basically like a human
> suffering from food poisoning! Lesson learned.
> Synth-diy mailing list
> Synth-diy at synth-diy.org
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Synth-diy