Wow! You guys are all super lucky to have moderately quiet birds!
This morning, I was woken up by Merlin SCREAMING, it was a level 8. He sleeps in our room with us and he was totally done with me sleeping in.
I'm not sure if him coming from a terrible pet store situation is why he is so loud, but I think hes louder than most. Some days are worse than others for sure.
He screams the ear piercing scream when; you try to sleep in on any day, when my hubs and I are both in bed on sat/sun morning, when the dogs try to eat the food from around his cage, when the dogs bark at things outside that he can't see, when my son gets too close, when we're in the next room and hes in the cage, when hes out of the cage, when any lights come on and stay on too late at night (you have 12 seconds), while I'm cleaning the cage out, if he even sees the vacuum- so bringing it into my room to vacuum is fun! When you fluff a blanket or ruffle through any basket of laundry. He has a real problem with clothes.
So days when I have to deep clean my bedroom and bathroom and his cage, I have to put earplugs in because its the only thing that saves my hearing and my head.
On top of his high decibel screams, he talks and chatters constantly. So there is always a stream of sound coming from that beak, and its hilarious! Hes loud enough, that I had to tell my neighbors that I have a macaw and not to worry when they hear screaming.

It was a really fun conversation when Merlin was screaming HELP constantly! He doesn't do that anymore, thankfully! I kept my windows open the entire autumn and everyone got an ear full.
I feel like I've read something that says the birds try to match the level of noise in their house? So if thats true, its no wonder he is so loud. We're loud, a loud kid, a loud pack of dogs, lots of loud. So I buy my earplugs in bulk.