Mono
Mono rendering ignores all audio sources’ spatial data and sums the scene’s audio channels together into one, optionally copying the resulting audio channel to several more.
Channel Count
The channel count parameter controls how many channels the mono rendering
will output. When set to 1, only one channel will be output. When set to 2
or higher, the sum of all sources’ audio signals will be output to that number
of channels with each output channel containing identical audio data.