Voice Coder = Vocoder - analyses frequency ranges from the original and transforms it to another frequency section
Note: Kraftwerk used a machine called Votrax (Siemens), its a phonetic Generator, so it is NOT a Vocoder.. but of course they also used vocoders (a lot)..
Homer Dudleys VODER is one of the first made (late 1930ies/ very early 1940s)
(the vocoder was invented for the war (again) to encode and decode spoken messages..)
And most poeple who tell about vocoders basically mean "there's some tech gadget mangling the voice" but - in fact it's often a harmonizer (indie / pop music / song writer), auto tune (Mainstream Pop), or just a reverb / distortion (EBM/Industrial) - but vocoders are those sounding like ... the Kraftwerk Robot thing and are sort of a singing synthesizer - it's basically checking a few frequency bands, exchanging those bands and playing it back replacing the natural sound source by a synthesizer (mostly pads with certain amount of upper harmonics like rich string pads) to reproduce consonants and s and f noises (which can be coloured noise but as a whole it must be something tonal if you want to play melodies). so there's an analyzing part and a synthesizing part, one that transforms the microphone (or drum loop …) signal into those band filtered 8 or 16 bands (sometimes more) and so to say "sorts" out which frequency group plays a role in your stream of speach / singing.. and afterwards that synthesizer voice plays it back, maybe you have assigned those frequency bands to other bands, so this makes it sound a bit different - note - this was made to chipher encode signals - so this is just a bit simpler because you still want something that makes sense "musicially". so - here you go - the oscillator is that synth carrier signal and will play as much harmonics as that back to the designated band.. and now you have it - we are the robot'sssss... some original direct signal will help to understand what your robot is saying..
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Korg VC10 1978/79 - 8 band, not routeable, (D) nicht routbar
Korg vc-10 vocoder .. eg used by Cabaret Voltaire..
