“The face is the index of the mind,” according to an ancient proverb. People with autism, however, are often unable to judge when a face conveys emotions such as happiness or sadness, and many researchers take this as evidence that autism involves serious deficits in processing social information. Yet the voice, too, can provide emotional cues, and several recent studies indicate that when listening to voices, people with autism can actually recognize feelings and other traits of humanness as well as—or even better than—neurotypical people do.
Read more: http://www.scientificamerican.com/article/an-auditory-component-to-autism/