Thanks guys, the nose assembly seems like it was definitely the issue. Using that, I was actually able to find a video online with a similar noise:

‪Strange noise on takeoff AA 737-800 MIA‬‏ - YouTube

Anyways, thanks again. I wasn't particularly worried as I know planes can survive pretty dramatic failures, I was just curious and found it very difficult to find any answers online. It seems like every website assumes people are freaking out about the air vents or just landing gear going up/down.