Screaming Bird

I'm sitting here tonight, watching my bird go CRAZY on top of her cage.. seen in this picture (shes in the top right hand corner on top of her cage).
While listening to her display and call I got curious and wondered how loud cockatoos can actually yell so I google searched it:

I found that Moluccans can scream up to 135 decibels (click on this to see the website I got it from) and I could not find what Umbrellas levels are.

Although birds can yell very LOUD, mine tend to quickly calm down with some attention and love: but when they are displaying flock behavior it is best to let them do what they want so they do not become aggressive towards you, as a small bite from a bird can hurt... A LOT.