Multi thoughts
I like to think that with four ears, each pair would have a different tuning to extend the audible range. Maybe a larger pair of ears that can hear 10~10000 Hz sounds, and a slightly smaller pair in front that can hear 40~40000 Hz sounds.
Likewise, multiple specialized sets of eyes can be neat as well. A pair of eyes that sees between 800~450nm in conjunction with a pair that can see between 650~300nm, for instance.
However little sense that makes biologically.
re: Multi thoughts
Most of the things I'm into I like because of how they expand possibilities. Multiple arms to allow you to do more things at once, multiple heads to let you look in several directions at once--and that comes with multiple brains to let you process multiple things at once. Modularity to let you change things out for different things, or just free your heads from their prison atop your necks.
