Many children with autism display reactions to auditory stimuli that seem as if the stimuli were painful or otherwise extremely aversive. This article describes, within the contexts of three experimental designs, how procedures of systematic desensitization can be used to treat hypersensitivity to auditory stimuli in three young children with autism. Stimuli included the sounds from a vacuum cleaner, blender, hand-mixer, toilet flushing, and specific animal sounds from musical toys. A changing criterion design was used and data were collected on (a) the number of hierarchical steps completed as comfortable with the stimulus per week and (b) the mean level of anxiety per probe. A clinical replication was implemented using a replication of the desensitization procedures for three children. In addition, a systematic replication across three different stimuli is presented for one child in a multiple baseline. The data show that the children's responses could be modified to the point where they were comfortable with these noises. Furthermore, this level of comfort was maintained at follow-up. The discussion suggests that the extreme reactions to auditory stimuli many children with autism exhibit may be decreased with procedures that have been shown to be effective with reducing phobias, and the possibility that the reactions may be symptomatic of a phobia rather than actual pain. (Contains 4 tables and 4 figures.)