PulseAudio: Mono-Sink Audio

Just in case your 10.000+ employee corporation doesn’t plug in the microphone-jack correctly and no one is allowed to ask questions (presentation-only).

Find the name of your audio sink by running

pacmd list-sinks | grep name:

Then run this command (taking care to remove the angled brackets):

pacmd load-module module-remap-sink sink_name=mono master=<name_of_audio > > sink_given_by_previous_command> channels=2 channel_map=mono,mono

or add the argument to pacmd to /etc/pulse/default.pa to have it run at startup.

Then in Sound Preferences choose “Mono” as the output, but remember to reduce volumes by half, since two channels are getting mixed into one, or else you’ll have distortion. To test, run:

speaker-test -c 2 -t sine

Same thing in a single command:

 pacmd load-module module-remap-sink sink_name=mono master=$(pacmd list-sinks | grep  -m 1 -oP 'name:\s<\K.*(?=>)') channels=2 channel_map=mono,mono

To remove the mono channel, just use:

pacmd unload-module module-remap-sink

Source: StackOverflow

Thanks to ondrejch!