It maybe be involuntary while it’s happening, but so is having a seizure, and that’s not a compulsive thing. That’s just a neurological reaction that sparks a physical one. With Tourette’s, it’s almost entirely defined by the uncontrollable urge to make a sound or move a part of the body, even if you don’t want to. With stuttering, it’s more passive. It just happens when we decide to talk. With Tourette’s it goes more to the conscious knowledge that they have the urge to make this sound or make this arm movement...they know all about their own tics. Involuntary can be a misleading term in this way.