LocalIn defines buses that are local to the enclosing synth. These are like the global buses, but are more convenient if you want to implement a self contained effect that uses a feedback processing loop.
There can only be one audio rate and one control rate LocalIn per SynthDef. The audio can be written to the bus using LocalOut .
The number of channels (i.e. adjacent buses) to read in. You cannot modulate this number by assigning it to an argument in a SynthDef.
The initial value written to the bus once, so that it can be used before overwriting it with LocalOut. An array can be passed in to specify different values for each channel.