LittleSiouxsie: " I am not against HE but it worries me that children who find normal life challenging are removed from it even more by being taken out of school and how do they then develop coping strategies? When and how will he make friends and accept the hustle and bustle of life? Is this not part of sport, play and growing up?"
I don't think so, no. The things which are bothering bizzey's son are not half so intense or prolonged in daily life as at school. Unless of course you choose particular careers, hobbies etc... but you won't do that if those things bother you. School is not "normal life". In many ways it is very different to the rest of life.
I can sympathise with the OP's son. I went all through school being bothered by the same things. Probably my reactions weren't as strong as his: I don't remember ever complaining to anyone very persistently about them; I just accepted them as an inevitable part of school life and was quietly miserable, occasionally faking illness to get a day of peace. When I left school I was overjoyed to find myself free from all of these things which had stressed me for years. Having to put up with them hadn't developed my coping skills at all. It was rather the reverse. How could I have developed coping strategies in a place where I had no control over my environment?
Friends, for instance. The real-world social environment in which I made friends so easily after leaving school was quite different to the school social environment in which I had been rather lonely.
Likewise, noise. I am not supersensitive to noise but the level of noise in a school playground far exceeds what I regularly encounter elsewhere. I do occasionally experience something similar: big parties, crowded buses, concerts, indoor children's parties with 30 guests. Those loud experiences tend to be brief, rare and mostly avoidable. Sure, if I chose to be a stockbroker, a pop musician or a kids' party entertainer I would have to put up with a constant assault from noise, but I don't!
Everyone accepts that many adults (like me) dislike a loud and busy environment and that it's OK for such people to spend their time as computer programmers instead of party entertainers. Children deserve the same respect for their differences. Why do we try to turn all of them into party entertainers? It isn't possible. 30 hours a week in the wrong environment won't mould them into different people; it simply makes them suffer.