If you have a pet dog (or used to) you will know that woofwoofwack means that your dog has decided to end it's life by getting his body stuck in the spokes of a car wheel. If your dog has made the noise "woofwoofwack" I feel very sorry for you.
Would you like to go play outside fido? Go on then go and play! ( A few minutes later) WOOFWOOFWACK!! My do has just died said bert with a tear in his eye.
A wuwuzela: The constant, highly irritating background noise created by crowds of people, usually women (AKA "woo-girls") and usually as audience members at TV shows like "Oprah", "Dancing with the Stars", "American Idol" and "The Biggest Loser", as they scream "WOOOOO!" enmasse.