A key indicator to clinicians making a proper assessment for autism would include looking for symptoms much like those found in sensory integration dysfunction. Children will exhibit problems coping with the normal sensory input. Indicators of this disorder include oversensitivity or under reactivity to touch, movement, sights, or sounds; physical clumsiness or carelessness; poor body awareness; a tendency to be easily distracted; impulsive physical or verbal behavior; an activity level that is unusually high or low; not unwinding or calming oneself; difficulty learning new movements; difficulty in making transitions from one situation to another; social and/or emotional problems; delays in speech, language or motor skills; specific learning difficulties/delays in academic achievement.
One common example is an individual with autism hearing. A person with Autism may have trouble hearing certain people while other people are louder than usual. Or the person with Autism may be unable to filter out sounds in certain situations, such as in a large crowd of people (see cocktail party effect). However, this is perhaps the part of the autism that tends to vary the most from person to person, so these examples may not apply to every autistic.
It should be noted that sensory difficulties, although reportedly common in autistic's, are not part of the DSM-IV diagnostic criteria for autistic disorder.