Have more time - longer post now!

So yeah, a friend's child was like this (don't get me wrong - I have very exuberant, noisy boys, but it's not a constant thing) and she spent a *lot* of time helping her child to learn "levels" of volume (level 1 was whispering, level 3 was "indoor" voice, level 5 was excited, outside voice.

My friend had no misconceptions that this was about naughtiness - it was awareness, and it became apparent that it sprang from hearing difficulties. Ultimately, after lots of specialist appointments, they got tubes in her ears. It took a months or two to acclimatise, but it's all good now

My little bro was similar - but he got labelled naughty, colour blind, maybe ADD - it was just hearing issues. He got tubes, realised it was that he wasn't hearing the teacher, the colour names, his own volume - same as my friend's daughter, after a little while everything fell into place.

Good luck!