Why doesn't our own snoring wake us up?

Why do some animals sleep standing up? And do fish sleep? Why are elderly voices higher pitched than younger voices? Why does the outside temperature drop just before the sunrise? Why do I feel pain in my ears during a plane takeoff, and why does chewing gum help? Do cats and dogs recognise their siblings? Why is yawning contagious? Do dogs get depressed? Why do we feel hot when the room is at body temperature? And why does our own snoring not wake us up? Dr Chris and Abongile Nzelenzele have the answers...