John makes the second round
Here's a description of the contestant's attempt. Someone's probably working on collecting some images to illustrate it.
John correctly guesses that the packet of cereal hitting the bar will be quieter than the sound of the horn. He then incorrectly guesses that the sound of an electric toothbrush being thrust into a bowl of marbles will be louder than the sound of the cereal, and is eliminated in the second round, earning second place.
(Written by Karl Craven)