2004 tahoe dvd plays with no sound

Just purchased 2004 tahoe lt with no operators manual. DVD player is overhead and car did not come with any headphones. I put the dvd in and no sound comes out of the speakers or if i put regular headphones no dvd sound comes out. I can put the headphones in the center console area and hear the radio, cd, ect..... I have looked online at an owners manual and it does not give any help. I hope this is just an operators error I do have a controller for the dvd player but no success with it either.
please help my kids are driving me crazy
Ryan
2004 Chevy Tahoe LT