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.pato 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
Thanks to ondrejch!