Digital Theater System "DTS" requires the following components in order to decode DTS sound:
1. A DVD player with DTS "Digital out".
2. A Receiver that has a built in DTS processor.
3. A DTS-encoded DVD disc.
If you have the proper equipment but still hear no sound, check that the proper digital output format of the DVD player is selected (see the owner's manual). Also check that the proper digital input is configured and assigned on the receiver, and that the proper connections are made.