There's no "er" and "th" in Japanese, so this happens. I actually know a lot of games/animes where voice actors pronounce it this way.
oh well (And by the way auditions are never like this from my experience)
And before you guys say anything yeah it's a Jojo reference obviously, and yes for some reason some of you guys thought it's dio but it's jotaro

If you want to download my album, try these links! (FOR FREE!)
SoundCloud
  / soras-full-album  
DropBox
https://www.dropbox.com/s/f6zj314mk9k...
-If You want me to voice something, I use fiverr
https://www.fiverr.com/sorathejapanes...