Bosch Appliances UML-273-90 installation manual Line-Out, and Internal

Bosch High Performance	Navigating the Monitor en 49
HD LED Monitors

Mute	Enables/disables audio. Choices are: On and Off.
Audio	Selects the audio input source. Choices are: Audio 1
Source	(audio signal from the Audio IN connector) and HDMI
	(audio signal from the HDMI connector).
Speaker	Sets the monitor to play audio using the external
	speakers, external audio devices (if connected), or
	built-in (internal) speaker. Choices are: External,
	Line-Out, and Internal.

Bosch Security Systems, Inc. Installation Manual 2013.02 3.0