Hi, Arik, good to see you here.
I'm doing the localization on two scales in the last 1.5 years: right whale in Cape Cod Bay and Chickadees in our lab's backyard. Both have different physical scales but share a common challenge: a tiny time synchronization error will result in a huge localization error. I agree that Eric's suggestion on 8-sound is only good for beamforming method, which is less accurate than TDOA(Time Difference of Arrival)-based method IF the sound recorders are synchronized. That's a big IF to me! At least beamforming method rely on the microphones connected through cables and thus no time sync issue at all.
If you want to sync through RF or some other wireless protocol, based on my experience it might be very difficult to achieve it accurately since you introduce more syncrhonization error in the process. In addition, to reliably estimate TDOA, you need audio signals to be transmitted to be in a single computer. Transmitting an audio signal quickly drains your power.
I've done a simulation how the lack of time synchronization results in the localiation error. A 1 msec delay in one recorder is enough to screw things up quickly for a diamond-shape 4-unit array.
I'm pessimictic for a sparse array with wireless time-synchronziation in an affordable price range. For the baleen whale monitoring in our lab, we're replacing the original clock by atomic clocks, which are expensive but reliable no matter what environmental conditions are. For terristrial application, I tend to go with cabled systems and do beamforming to avoid the time-sync problem. It sounds technology backward but offers scientific location data of better quality. Scientific advance is what matters, isn't it?
Postdoc, Cornell Univ.