HP Compaq S2021 20-inch Widescreen LCD Monitor - Manual (Page 17)

Connecting the Audio Cable (select models)
Connect the built-in monitor speakers to the computer by using the audio cable, as the
following illustration shows
Figure 3-7 Connecting the audio cables (select models)
NOTE: When using a VGA or DVI signal, you must connect your audio separately because a
VGA or DVI signal converts only video data, not audio data.
ENWW Connecting Cables 11