Communication is a crucial part of everyone’s life, yet millions of Americans suffer from communication disorders. In fact, stuttering affects about 1 percent of the U. S. population. Dr. Dennis Drayna, of the National Institute on Deafness and Other Communication Disorders, explains how genes affect the ability to communicate and discusses his work with stuttering and disorders of pitch recognition, also known as 'tone deafness.' From the Series:2002 Medicine for the Public Lecture Series