Background: auditory hypersensitivity in the autistic spectrum disorder has been described in the literature since the very first reports. However, this symptom has not been sufficiently explored, especially regarding possible causes, diagnosis and consequences.
Aim: to study sensory-perceptual abnormalities in the autistic spectrum disorder, emphasizing auditory hypersensitivity and to discuss their effects in speech therapy based on the literature found until September 2007 in the following database: Scielo, Lilacs, Web of Science, and Medline.
Conclusion: sensory-perceptual abnormalities are present in approximately 90% of individuals with autism; no theory has been found to explain this fact. Although the cause of auditory hypersensitivity remains unknown, it is the most common sensory-perceptual abnormality--its prevalence ranges between 15% to 100%. A few rare studies exist on behavioral, electroacoustic and electrophysiological hearing evaluation of autistic children; these studies discuss auditory hypersensitivity. The early diagnosis of this alteration is considered relevant for the possible identification of atypical sensorial markers, especially in hearing and for the better understanding of their impact on the development of communication in autistic individuals.