If
your computer presentation includes sound and you did not connect
it to the projector's
DisplayPort or HDMI port, you can still play sound through the
projector's speaker system
(PowerLite Pro
G6070W/G6170/G6270W/G6470WU/G6570WU/G6770WU). Just connect
an optional 3.5 mm stereo mini-jack audio cable as described here.
Note: If your
projector does not have an internal speaker system (PowerLite
Pro G6870/G6970WU), you can play sound by connecting
external speakers to the projector.