It's a bug. Pretty sure you can just delete the files out of tori or Uke's folders. I think that's how it works still. Either that or the players with the custom sounds folder.
Glad to see someone else is getting this. I was bugging JTank about it last week.
Deleting your customs folder doesn't work, neither does validating your steam files (reinstalling)
I fixed it temporarily with the /dl command but it comes back within a day.
The only real fix for me so far has been disabling grab sounds, kiai and hit sounds, however this tends to make me forget I'm playing Toribash when I tab down after losing.
/me pushes suggestion of disabling custom sounds in options