What is AudioInput?

[Orboscope]

In the oscillatorsection you can choose AudioInput amongst the other modes like basic and additive.
Or in the layersection you can choose it where you can add suboscillators.

Yet when you acctivate it, the result is simply no sound. The manual is useless in this respect.
Where can I define what the source of the audio for the AudioInput is?

[onerob]

You can add SynthMaster as FX plugin and have the track audio be routed through the FX page.