Mostly used by macintosh users.
While listening to a podcast or any other audiomaterial hearing the twitterific-, mail-, ichat-, adium-, skype-,
or whatever notification sound from one of the podcasting people and thinking it's a sound from your own computer
– but it is not.
It's related to notification paranoia.
Paul: "Everytime I'm listening to the RebelFM podcast I hear my mailprogram receiving new mails, but It didn't."
Mary: "So you fall for a fake notification?"
Paul: "Wait a sec, I heard a bird tweating"