Synthesizer voice

A synthesizer voice is an individual audio circuit path that produces an individual sound.

Signal flow
Even with multiple oscillators, a typical monophonic synthesizer has a single voice and only one key at a time can be used to sound a note. On a polyphonic synthesizer, as many keys will sound simultaneously as the instrument has voices.

The simplest standard voice is made up of a VCO, a VCF, a VCA and the envelope generator to give the note timbre and dynamics (changes in loudness). In a polyphonic synthesizer, each voice is a parallel signal path with its own oscillator, amplifier and filter. A paraphonic synthesizer plays several notes at once, however they all go to a single filter.

Sometimes voice is also used to refer to a patch or a preset instrument sound.

Rather than have a voice for each key, a polyphonic synth's keyboard will allocate a voice to whichever key is pressed. Exceeding the maximum polyphony results in voices cutting out abruptly.