Many people on the spectrum have one or more exceptionally acute senses, called ‘sensory hypersensitivity’. Baron-Cohen and colleagues mention research which found this for several senses. People on the spectrum, for instance have more often perfect pitch than the rest of us. For instance, some people on the spectrum can distinguish between dozens of vacuum cleaner brands. For more about sound perception see here.
Also many posses exceptionally good eye-sight. One study shows that people with high-functioning kanner-autism and Asperger’s can see 2,8 times more sharply than average, comparable to the eye-sight of an eagle. Baron-Cohen et al also mention touch and smell.
These observations are not at odds with other information (see here) that under-responsivity to sensory stimuli is fairly common among people on the spectrum. Firstly, under-responsivity of one or more senses does not rule out the possibility that one is overresponsive with respect to other sensory stimuli. Secondly, under-sensitivity is partly age-specific: especially children are under-responsive, with a peak between 6 and 9 years of age.Baron-Cohen