There was an owl hooting outside our house earlier, and it occurred to me that every other bird has a high-pitched call.
Ravens have a croak that could be considered low, but their loud call is a caw that’s higher. I can’t think of another bird with a call nearly as low as owls’.
Search engines are no help, mostly duplicates answering why they hoot. Why are owls’ calls so much lower than other birds?
Owls of MN and Their Sounds
I want to get you a more in depth answer on your actual question, but I’ll have to do that later today. In the meanwhile, this is a quick guide to MNs owl sounds.
Your particular owl I’m betting is a Great Horned Owl. That’s the one I’ve got in my neighborhood in southeast PA. I figured out it was him but googling “Pennsylvania owl that hoots 5 times” and that sounds like exactly what you have. It also seems to be the most common owl in MN, and since GHO has no predators, they get to be more vocal than many smaller owls.
My wife has an app for recording and identifying birds. Like Shazam for birds. Sadly, she’s smart enough to not be awake at 2am.