Hello, well I don't know if it could mean he has some other issues going on but he does sound an awful lot like my toddler.
I mean we don't have the constant shouting but when he is really tired (which is often - he doesn't sleep well - and has never been settled, cried a lot etc) he will get very stroppy.
I think you have sometimes to lower your expectations and do very little of the things that set him off, if at all possible.
I find we often achieve very little during the day - I am SAHM - but he will sometimes watch the TV for a while which is bliss, otherwise he wants to take things apart, break them, tear off wallpaper and draw on the furniture.
He is dreadful - I was cleaning one bin this morning while he was busy shoving chocolate spread all over the other one. It never seems to end - and 'wash your hands' ends up being water all over the ceiling, his clothes, etc etc.
I find two things help. Food - always making sure they don't need a top-up - and sleep, and the combination of eating/drinking plus exercise can send him off and then he is much much nicer.
It will pass though, normally - this is a normal stage - could he be cross and frustrated about going to the CM, or about his hearing? That might just be exacerbating it a little iyswim. (Mine got very cross after he had been at Grandma's without me for a few hours - like a reaction to feeling worried when he was there - we aren't doing that now, till he is a bit bigger)