Vocoders are the synthesiser version of bagpipes. They make me cry and Iโm not thinking of bonnie Scotland.
There are three reasons why a vocoder might be acceptable –
- You are Kraftwerk or YMO.
- You are old-school vocoding a sound with another sound.
- There is no third reason.
It’s true that vocoding was initially developed as a means to transmit voice efficiently over a distance, and therefore is attuned to vocal elements and frequencies. However it is a general principle in synthesis – any sound can be vocoded by another – which is what I mean by ‘old-school’. For example there’s been a fair amount of drum machines run through vocoders – but there’s no reason why it should not be considered part of synthesis in general.
On some synthesisers you can find vowel filters which approach this effect, or better spectral filters that can hold a complex signal. Less hardware machines allow patching of synthesis through a vocoder stage. With some careful planning you can vocode one layer of KORG’s RADIAS with another – which sounds impressively horrible. The Radias also has remnants of the ill fated Yamaha FS1r – storing ‘vocal phrases’ as vocoded articulation.
The robot voice has been around since the 1939 World’s Fair. Do you really want to sound like you are from the Thirties?
Unfortunately manufacturers follow fashion, and that being the robot voice a majority of synthesisers have a specific mode where a microphone modulates synthesis to make yet another robot voice, which then reinforces the basic idea.
There’s another form of sound design called Phase Vocoding which requires extensive calculation. The most obvious use of this technique is in time stretching and pitch shifting, but there’s a wide variety of possible synthesis effects.