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The vocoder - how to turn the sound of any instrument or sound source into speech

The vocoder – how to turn the sound of any instrument or sound source into speech


I have three words that encapture the vocoder in all of its essences…

Sparky's Magic Piano

An amazing sound, and produced as far back as 1947 by Alan Livingston. The gadget that turned piano playing into speech is the Sonovox vocoder. A vocoder can take any sound that is rich in harmonics and superimpose a pattern of speech on top of it.

The concept behind the vocoder dates back to 1939 with the Voder, developed by Homer Dudley at Bell Laboratories. The voder was a manually operated machine that could be 'played' and produce speech sounds.

You can hear an example here…

The voder was a staging post towards the vocoder, which is a contraction of VOice CODER. The purpose of the vocoder was in telecommunications. The idea was that speech could be captured and analyzed, and the information transmitted using a narrower bandwidth than natural speech would take up. The sound of speech would be resynthesized at the other end.

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Had this been economically feasible, it might have led to a single telephone cable having the capability of carrying two conversations simultaneously.

Unfortunately for Dudley and his team , the vocoder remained a curiosity in telecommunications. In music however, the vocoder has been very popular over the years.

Every so often a vocoder record will be released, such as Sparky's Magic Piano, and it will catch the public's ear and sell in vast quantities. The Electric Light Orchestra's Mr. Blue Sky is another good example.

The vocoder takes two inputs. One is the speech input – you don't have to sing into it. The other is the sound onto which the characteristics of speech are to be superimposed. This sound has to be rich in harmonics, otherwise there is nothing for the vocoder to work on.

Currently available vocoders include the Akai DC Vocoder VST plug-in. For hardware lovers, there is the Korg Microkorg, which incorporates a vocoder, and has a handy built-in microphone.

Korg Microkorg

Possibily the reason why the vocoder comes and goes in popularity is that when someone uses it, they overuse it. The vocoder is capable of very subtle sound shaping, as any harmonic structure that can be created using that most versatile of instruments – the human voice – can be applied to any sound source.

Why haven't you got one?

David Mellor



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David Mellor