Higher sensitivity to everything especially sounds. The problems with all types of sounds including music are typical for the children with autism syndrome. They can perceive speech and some other calm sounds like relaxing music, but sudden loud sounds may toss them away. Kids with autism fear noise. As the time goes by, some patients learn to block all forms of sound. It allows focusing on the important things like healthy sleep.
People with autism tend to repeat some actions and phrases. They may forget that they have already done something. Repetitive behavior patterns are symptoms of autism as well. For instance, the autistic kid may keep walking around the room without any specific intentions or typing in the same letters on PC over and over again, without finishing the intended message. Sometimes, such children repeat certain things because they consider them fun. It is hard for them to adapt to everything new.