
Hi Pru,
it sounds as though this is a nervous reaction :( Has something happened recently which could have knocked his confidence a bit? Perhaps he's associating particular noises, say particularly low velocity sounds such as coughing, with an unpleasant experience? It might be worth thinking back on recent times to anything, however small, that may have unnerved him and what that trigger might have been. You don't say how old he is - it may also be that his hearing is not quite as good as it once was and between that and his blindness the world is generally becoming a scary place for him, hence the seeking out tight places etc :(
Hopefully you can provide more info and someone else will be along soon with advice. If it seems to be a nervous reaction, there are several homeopathic remedies which may help him relax a little.
Good luck, Teri :)