Looking in a dictionary, he's asking, this person is human? what's with the weird sound (nakigoe according to jdict is a cry of an animal, ie, bark, howl, chirp, etc), ie, why is this human making animal noises? the response (since he's a programmer and thinks akuto is bugged) is close, he's saying don't call it nakigoe, is your head bugged (or is there a bug in your head)? Fumyu I assume is supposed to be some cutesy sound the character makes and Akuto mistakes it thinking it's some weird noise