shaquille o'neal to name a few who overcame their speech impediment impediment. he mentioned from time to time even as an adult he suffers from it when he gets really excited about something or he wants to tell somebody a secret then it kind of cops up again. >> rich besser is here right now. we heard how common this is. what do we know about the causes. >> it's early days and fully understanding it. when we're talking about stuttering we mean problems with the flow of your speech and the rate the rhythm getting stuck on certain word certain sounds. and when you look at causes clearly genetics is part because it runs in families but there are environmental erins that play in as well. a lot of stuttering is normal development. you know kids they're learning so many words and probably not able to say them as fast as their brain is taking them in and then their neurologic conditions are pretty rare as a cause of stuttering. >> ed gives a lot of credit to eminem -- i say slim shady because i can't say eminem. is there really a correlation between stuttering and music?