Behaviour - teacher treats my child's behaviour as 'naughty'.

My son is 7 years old and has a diagnosis of Asperger’s Syndrome. He attends a mainstream school. His class teacher treats him as a naughty child as he makes a lot of noises and flaps in class which she says distracts the other children. I feel he has no control over these noises but his teacher says this is him being defiant. I do not want to jeopardise my relationship with the school but I need to address this issue. How should I approach this?