Trivia: S.E. Hinton, the author of "The Outsiders", has a cameo in the scene where Johnny is lying on his stomach in hospital, playing the nurse tending to Dally who says "what did you do with your gown?"
Visible crew/equipment: When Pony Boy, Dally and Johnny are pulling up to the burning church, just before the first one jumps out of the car if you look through the windshield you can see the water truck that's going to put out the fire after they shoot the scene.
Answer: Johnny is recalling the argument he heard his parents having; the voices were meant to sound angry but not to be understood. Its to help us understand his horrid home life.