Traditionally, DAWs use the acronym ADC (for Analog to Digital Converter)
to refer to the audio signal from your system's audio input device.
Far be it from us to stir those waters.
You can have multiple Hz.ADC instances (typically 0, 1 or 2) in your scene
to capture signals from your system audio input devices.
// This JavaScript snippet creates a mono audio signal src from
// channel 1 (the Right channel) of the selected, presumably
// 2-or-more-channel, Audio Input.
let adc = ascene.NewAnode("Hz.ADC",
{cfg:"mono", preset:{numchan:1, chanoffset:1}});
// now wire adc into your scene.