Switch audio outputs without using the GUI dialog for PulseAudio
You might find your solution here:
Audio output device, fast switch?
or here:
How to change pulseaudio sink with "pacmd set-default-sink" during playback?
You might find your solution here:
Audio output device, fast switch?
or here:
How to change pulseaudio sink with "pacmd set-default-sink" during playback?