My friend thinks that his child can hear frequencies that are inaudible to other humans because of which he sometimes reacts with alarm that no one else understands. Is there a way we can verify this systematically? In my electronics lab during my undergrad one of my friends tested my hearing by varying the frequency output of a signal generator. Is there a possibility of doing that on a PC?
Also, I would highly appreciate any references on music therapy for language delayed children. I am interested in vocal music training in particular but would appreciate any general music training as well for therapeutic purposes.