Child With Narrow Ear Canals

The child's brain is working very hard to understand the signals his ears send his brain. Narrow ear canals physically alter a child's perception of sound. He will hear high pitched noises loudly, but be almost deaf to some of the most important sounds related to speech. If parents are showing pity, their brain might not fully be able to handle the information he is receiving. thier brain will grow to make all noise perceptually louder. Meltdowns are quite disturbing and the child may need to be protected from both over and under stimulation. The child may even experience and adjust to pain from sound to the point they appear insensitive to other forms of pain.

Link showing females hear differently from males.
http://www.mcrcad.org/2010-Sax-hearing.pdf
Link with image showing that high frequency sounds have shorter wavelengths than low frequency sounds.
http://faculty.cord.edu/manning/physics215/studentpages/angieevanson.html