Head Canon and A Wish for Slash?
Head canon (that propbably is canon)
Due to Slash haveing a more anamalistic mutation then the turtles he is hard of hearing, at least to their standards, realistically his hearing is no different then it was before his mutation.
and i fear my point was proven by this scene
as Slash just keeps walking to beepop and rockstedy while Leatherhead notices the rapidly aproaching vehicle before they both get hit XD
gosh this was a hard question i dont really know how do awnser.
if anything i wish for Slash to gain immunity to all mind control
please... i beg leave him alone!!