That's gonna be rough. Up here we are used to really loud planes and the Naval Air Station do Ya some really noisy aircraft. Paine Field isn't very far away and it has tons of giant passenger planes coming and going, testing, etc. It's got Tramco that does annuals on the big birds, so, we are kinda used to extremely loud aircraft. Also, it's not nearly as populated as Seattle, lots of trees. I'd be surprised if anyone was woken by it. It takes time for these rockets to get supersonic, so that would be another factor. They unfortunately picked an ideal spot to launch. Don't forget the exhaust is pointing nearly straight down too. It would have been very brief.
Look at the launch videos, it's no Titan or Space Shuttle.