C.H.
Kids with sensory issues sometimes need an "outlet" for their energy and like you said deep pressure by lying on a bean bag or between pillows with you gently pushing on the top one is great - rough play may be teaching him about hurting his friends by "accident" and although done with good intent may not be teaching a child with sensory issues how to correctly get his needs out. For the voice - try giving him gum or even a "chew toy" where you give him a rubber string type device he can chew on (get them on line). Getting his hearing checked like another said is also a good idea. Teaching him cues that he can respond to like when he yells putting your hand up or with 3 fingers etc to give him a visual clue that he is being too loud would work - and is easy for all teachers, staff, and people with your son to do! Good luck!