Alfie does similar when he's feeling particularly hormonal. He went through a stage last year where whenever I walked into the room he would start making similar noises, wings would be drooped and if I stood near his cage for long enough he would regurgitate food for me. So I'm guessing it's a hormonal/mating type of behavour?
I'm no expert but if he started drooping his wings and making the noises I would back off from his cage (or wherever he was located) and give him some time and space to calm down.
I also had to be careful what toys I gave him - anything small enough to be mistaken for an egg would set him off and he would get over excited and try and guard it/sit on it. Those kinds of foot toys were removed to discourage the behaviours.