strange noise

yesterday and today i've been awakened by this loud noise, which i thought was a bird. more specifically, an owl. i've only heard an owl a few times before, and that was in rochester in our backyard (a great horned owl).

the noise started both days at 10am. yesterday it only continued for a few minutes and today it was about an hour. i've been trying to think of what it could be. here is what i thought:

it's not human.
it's not any other kind of bird except owl, because it's too low.
it's not a raccoon.
it's not a bear.
it could be a dog, but probably not. too calm and not dog-like.
it's not a rabbit because they don't make sounds.

so i guess it was an owl. now, i went online and looked for owl calls, and the sound i heard matched a great horned owl again. it was a tiny bit different because the one i heard was the exact same note over and over again and the one online was slightly different notes. they only had three calls, but the one called "harnk" was most like it. what's that? no idea. i couldn't find many other owls that live around here, and if there were some, they sounded completely different. i just read something that said that sound was rare. hmmm.

another thing: why is it calling in daytime? my guess: it must be hurt. i may go out there and look a little later on, if i have time. i know it's right around my window because it's VERY loud.