Decibel Vision eBook by Mark ElsdonWhat's Is Decibel Vision? The performer opens the phonebook on his phone to a contact labelled simply as The Psychic. This contact stays open and everyone can clearly see what the number is. Remember: the Psychics name and number are known to everyone BEFORE anything else happens. From a borrowed, shuffled deck a participant freely chooses a card. He then adds a bunch of other cards three, four, five, six, seven, eight, nine, ten as many as he likes.