If you are at all concerned about this then would advise that you took him to the vet or if it is totally out of character is best to get it checked out.
Oh its totally IN Character - he's a Birman , who are renowned for shouting. There is nowt wrong with him , he is just , shall we say , 'High Maintenance'
His latest foible is demanding dinner , eating three mouthfulls , then wandering off and 20 minutes later shouting for more food. Unfortunatley he has yet to realize that with four other cats about his chances of any dinner being left are few so we now have to feed him a third of a pouch at a time. He still refused to eat anywhere but in a bed - he chooses which one!
He is still my fluffy little fairy-cat tho!