A voice in a synthesizer is a standalone sound-generating or sound-processing unit that can create sounds independently. How many sounds a synthesizer can produce at once is determined by the number of voices it has.
For instance, a synthesizer with four voices can simultaneously produce four different sounds. This can be used to play multiple notes simultaneously, such as when playing a melody, or to create complex and layered sounds, such as chords.
One can also refer to a synthesizer as polyphonic if it has several voices. Monophonic refers to a synthesizer that can only play one note at a time. It is possible to switch between monophonic and polyphonic modes on some synthesizers.
Depending on the synthesis technique it employs, a synthesizer can produce a variety of voices. Oscillators, filters, and envelopes make up the voices of some subtractive synthesis synthesizers. Some people create voices using wavetable synthesis, which uses wavetables, filters, and envelopes. Granular synthesis is a synthesizer in which the voices are composed of grains, filters, and envelopes.
Additionally, some synthesizers have features like voice layering, voice stacking, and voice splitting that let you use multiple voices in various ways. For instance, you could layer various sounds to create complex timbres or divide the keyboard into different zones and assign multiple sounds to each zone.
Generally, a synthesizer’s capabilities and the types of sounds it can create depend on the number of voices it has and the voices it employs. These factors should be taken into account when selecting a synthesizer.
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