True, but I don't see how that itself would help sonar. Maybe some kind of triangulating microphone equipment. It must be related to the Pods in some way, though, because it beeps faster as one approaches.
Aha, maybe the light and beep are merely discernable indicators that the trap is sending off a sonar of its own, which is picked up by the Pods. This would imply Munch's SkullJack can also detect these sounds.
Another trivial and pointless fanboy puzzle explained.