After a couple years of use, my headphones finally broke -- the band that held them together above my head snapped in two:
The original broken headband.
The audio still worked, but they no longer sit nicely on my head. I looked online for solutions, but my headphone manufacturer wasn't selling a specific replacement for this part. However, I wasn't the first person this had happened to, and luckily some kind soul had made a 3D printer model for this piece and posted it online. With the help of the Shapiro Design Lab Staff, I was able to get a print of this piece:
The printed band - with supports still attached.
After removing the supports, I was able to take apart my headphones and try out the part. It wasn't smooth sailing initially, and I had to return to the lab to use their tools to sand the part down further so it would fit properly. The screw holes in particular were finicky, but eventually, I was able to get it to fit nicely and put it back together. The headphones fit great, and now they have some DIY flair to them with a different color band. I wouldn't have been able to get it done without the support of the staff; thanks to everyone who I talked to for your help!