Chaoseum are super talented,id recommend any of there videos, hopefully the rest of the world will discover them, sooner than later,nice to see you actually enjoying it too😉
The whispers are 'smile' on the right side and 'hit me', 'hit me' and then 'one more time' on the left side. Definitely heavily influenced by Korn, although this song has the strongest influence. I'd probably recommend Unreal or Stick Under My Skin as follow up songs.
To me they are very early 2000's, Nu Metal sounding, reminiscent of Korn, with maybe Seather (as you suggested) and early Drowning Pool mixed in? Just my thoughts, as I've never heard them before either, but was a big fan of metal in that era.