Well I think they should've added this effect because it could make going underwater a little more unique. Also I don't think big ears would do nothing more than hold some water after the nichelings got out. So I decided why not underwater echolocation, because underwater hearing doesn't sound right personally. So yeah underwater Echolocation works like hearing, but underwater. Ground breaking right. So hope this was simple and a little interesting, Sincerely Biogamer.