Dear T.,
It would certainly appear that your child does indeed have very hypersensitive hearing. If so, this is an issue in the midbrain. It is a relatively common issue and one that can be dealt with through a program to increase neurological growth in that area of the brain.
I know how difficult this is making your family life, and it may only worsen as he gets older for social situations.
I am a neurodevelopmental therapist and deal with problems originating in the brain. The brain has specific functions related to specific areas of the brain which should be realized within a certain age range. If those functions are not happening as they should, stimulation to that area of the brain with a specific program can help address those issues. This program teaches parents how to help their children right in your own home---no running around to different places. We put parents in the drivers seat.
You can begin helping your child right away once you have the information and some guidance on how to begin.
The amount of information is large, so I teach a class to present it in an orderly, understandable fashion. The next class is this Saturday from 8 am to 4 pm at 400 Chisholm Place, Suite 400. The tuition is normally $99 per couple, but for Mamasource members, I will offer a 50% discount to $49 for the upcoming class.
I understand what you're going through and I can help you help your child.
P.S. Just re-read your initial post and want to add that your child's issues can be helped with the proper stimulation in respect to the brain. I sincerely hope you will consider making the effort to be at the class on Saturday---you will understand so much more about him by the end of the day.