The Elephant Listening Project was on the popular American television show 60 Minutes last weekend. A little surfing on seismic communication among elephants turned up reporting on research by Caitlin O'Connell-Rodwell: (1), (2) and (3). Also, see O'Connel-Rodwell's review article, Keeping an "Ear" to the Ground: Seismic Communication in Elephants.
A couple of lines of inquiry. First, is "listening" at bottom a too comfortable metaphor for conceptualizing how elephants perceive seismic vibrations, how they live with vibration? In any case let's ask ourselves what listening could possibly be. Second, elephants can apparently recognize each others' "voices." (This too, this thing we call "voice," among the metaphorical—even as we learn that voice may be something that develops "in" nature, as if nature had no concourse with imagination.) "I know you." "I recognize your vibration." "I hear your voice." And already I have gone too far. Does an elephant say "I"?