We may start looking at auditory signs of autism based on two recent discoveries. One is that autistic people hear more sounds than do neurotypical people. The other is that the reason for this is that inhibitory pathways in the brain are weaker in autistic people.
Readers of this blog will not find the latter to be the least bit surprising. Weak inhibitory neurons would of course create more intense experiences of sensory input since inhibitory neurons dampen out information. They quiet things down, so to speak.
With weak inhibitory neurons, the excitatory neurons are necessarily going to dominate. This creates positive feedback, which makes for a more intense experience of one’s senses.
The first article also contributes to the increasing number of sources touting the positive aspects of autism. They point out that autistic people often do better than neurotypical people on visual and/or auditory tasks, spotting more continuity errors in videos and being more likely to have perfect pitch. I have little doubt that my high-level skills in proofreading have everything to do with my autism. Taking in an processing more information has its advantages.
Unfortunately, that “more information” doesn’t seem to include human faces.