I know this sounds like a strange question, but what is the difference between regular vocalizing and screaming? When Dino "whistles" the few little notes I taught him like the wolf whistle and similar 2-7 note whistles it is soft and pleasing. He also does some other sounds that are louder but not quite whistles - more like chirps and chirp-grinding-growling type sounds. Those are not soft and pleasing but louder and funny/amusing to hear a sound like that come from a little bird. I think the screaming is of course the loudest and most annoying, its more monotone and each sound is a couple of seconds long, repetitive and almost urgent sounding. The sound he makes when we leave the room is urgent sounding with clustered quick notes a pause and clustered quick notes.
He makes all the sounds (except the one when we leave the room) when we are in the room with him - especially the screaming

He does it for hours at a time, drapes open or closed light or dark doesn't seem to matter. It is driving S.I crazy
Any suggestions?
Jo