Tourette syndrome (also known as Gilles de la Tourette syndrome) is a neurological disorder that causes tics. It is common in children, adolescents, and adults.

Many people find sounds like fingernails scratching on a board, the "squeaking" sound of an aluminum pot or pan hitting a tile floor, or simply the "clicking" sound of a ballpoint pen, and just thinking about it makes them feel uncomfortable, even disgusted.