I have two blue crowns. 90% of the time the noise they make is not bad at all. Blue crowns have a harsher call than some other parrots so it can be hard on the ears at times when they get wound up. The pitch of their noise is more in the mid range. The noise does not go through walls as well as a higher pitched call like my Senegal. I can hear his high pitched squeals down the street but can't hear Tootsie and Rosco until I am close to home.
My two birds have differences in the amount of noise they make. Tootsie is a squawker. She. Does. Not. Stop. She seems to have a need to make noise continuously. Rosco is much quieter in comparison. He usually seems to take his cues from Tootsie. She squawks and he will join in having no clue what he is squawking about. Tootsie accounts for about 75% of the noise between the two of them.
The following video is Tootsie and Rosco going off one night. Remember that they are feeding back on each other and amplifying the noise more. Note that as quick as it started, they finished up and calmed down and they spent a quiet time after preening each other. That is the blue crown version of "singing", I think.
Tootsie and Rosco make noise! - YouTube
Now, they can also have their really cute times. This video is a fairly good example of them during a "normal" noise making session interacting with me.
Tootsie and Rosco - YouTube
And this last one is Rosco "chatting" with me.
Chatty Rosco - YouTube