No audio. we got a new dvd and slipped it into our player and changed our "source" until the

Question

we got a new dvd and slipped it into our player and changed our "source" until the picture came on, just like always. But can't get the sound on the television to work. This has happened to us before and I thought there was something real easy we did to correct - but we can't remember what we did. so now we are sitting here w/a movie we want to watch and no volume on it.