Stuttering, also known as stammering, is a speech impairment where the person has disrupted speech due to prolongation of syllables, words, sounds, and repetition of sounds or words, which is always involuntary. The person also suffers from periods of silence where he is unable to produce any sounds.

This form of speech impairment does not affect a person's intelligence. The only problem a stutterer has is that he is unable to put his thoughts into words. A stutterer does not always stutter; instead the problem becomes obvious only in certain situations like talking on the phone, being anxious or talking in front of a group of people.

Usually stuttering occurs in childhood and can be resolved with proper speech therapy. However, it can be acquired in adulthood due to head injury, tumor, stroke and drug abuse.

Here are some famous people with speech impairment:

• Bruce Willis: A famous Hollywood actor used to stutter in his youth and was afraid that it would affect his prospects as an actor. However, he overcame the impairment without therapy. He said that he lost his stutter because of acting.

• Tiger Woods: One of the best professional golfers of all times, Woods used to stutter as a child. However, he overcame the problem with therapy, which included talking to his dog until he fell asleep.

• Julia Roberts: This famous Academy Award- winning actress used to stutter when she was younger. However, she does not talk too much about it. Today, she speaks fluently and there is no sign of the impairment.

• Anthony Quinn: This Hollywood actor started acting in 1936 and gained a lot of popularity for his mafia roles. He used to stutter as a child but overcame the problem with proper speech therapy.