1 example for pactl

  # set up pulse audio server
# list all sinks
pactl list sinks

#Change the default sink (output) to 1 (the number can be retrieved via the `list` subcommand):
  pactl set-default-sink 1

# Move sink-input 627 to sink 1:
  pactl move-sink-input 627 1

# Set the volume of sink 1 to 75%:
  pactl set-sink-volume 1 0.75

# Toggle mute on the default sink (using the special name `@DEFAULT_SINK@`):
  pactl set-sink-mute @DEFAULT_SINK@ toggle