So apparently your voice can be copyright claimed on YouTube. I was testing my mic filters on a private stream and after I was done it got claimed by CD Baby.
Really @YouTube @TeamYouTubepic.twitter.com/k7EwoPGwSn
Had similar stuff happen twice in a row with visuals (not music, freely available stock footage) of a firework on YT. The claimant in my case was a big cupcake channel. As I needed the video up ASAP, I didn't dispute the claim but exchanged the footage for stills instead.