You
can play sound through the projector's speaker system if your video
source has audio output ports.
If you are
projecting video using a Computer
port, connect the projector to the video source using an optional
stereo mini-jack audio cable.
Note: If you
connected your video source to the projector using an HDMI cable,
the audio signal is transferred with the video signal; you do not
need an additional cable for sound.