Vocal tics are sounds that a person with Tourette syndrome might make with his voice. Throat-clearing, grunting, and humming are all common vocal tics. A person with Tourette syndrome will sometimes have more than one tic happening at once. The type of tic can change, and how often the tic occurs can also change. Tics are made worse by stress, like studying for a big test.
Tics always disappear during sleep.
People with Tourette syndrome can force their tics to go away for a few minutes or even a few hours. But the tics always return and may be worse right afterward. Sometimes a person with Tourette syndrome will have a simple tic - this means that it is a single sound or it involves only one muscle group. Another person might have a complex tic. This means making more elaborate motions and sounds, like repeating his own or other people's words or phrases.