L322 Necvox roof mount DVD no sound?

Hi, not exactly a critical issue, but my 03 td6 Had a drop down necvox DVD player in the rear roof. It appears to work ok, except I don't have any sound. Should it use the car speakers, or infrared or Bluetooth headphones? The original radio unit has been replaced with a Panasonic touch screen thing so I also appear unable to set trip computer options or the analogue timeclock.any suggestions gratefully received. The children would like to be able to hear Peppa pig!