Vocal & Ensemble Keyboard

Q.What is a vocoder?


What is a vocoder?

The "vocoder" was invented by the physicist H. Dudley in 1939 as a technology for compressing a voice communication signal. Subsequently, musical instruments based on this technology were developed, allowing you to play melodies and harmonies using a human voice. Of course, the audio source can be anything (not just a human voice) but because the vocoder has its basis in the sound-producing structure of the human voice, we'll be talking about it in terms of how a human voice is produced.

If we ignore differences of loudness, pitch, and variation between individuals, the waveform produced by our vocal cords is essentially identical regardless of what you're saying (e.g., "ahh" or "eeh"). We can distinguish spoken or sung words because of the various resonances (formants) created by our vocal tract (the shape of our throat and the movement of the larynx and mouth) and additional sounds called "fricatives," "plosives," and "sibilants" that are added in varying ways over time. The effect of the waveform created by the vocal cords actually has a rather minimal effect on what the listener hears.

A vocoder analyzes these time-varying changes, electrically synthesizes the shape of the throat and movements of the mouth (the formant movements), and uses these formants to modulate a musical signal (the carrier) rather than the waveform produced by the vocal cords. The vocoder "voice" produced in this way was closer to that of a robot in a science fiction movie rather than the voice of an actual human.

For your reference: The VP-550 and Vocal Designer technology.
In the VP-550 Vocal & Ensemble Keyboard, Roland integrates the function of the traditional vocoder with the revolutionary new Vocal Designer technology. Vocal Designer uses cutting-edge human voice modeling to bring about a revolutionary leap in the accuracy of the vocoder synthesis, generating a "human voice" that is far more realistic and natural than the sounds produced by vocoders of the past.


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