Black-eared Cuckoos are part of the Bronze-Cuckoo group and their calls have a similar structure. The main territorial call (samples 144-220 and 038-150), presumably given by the male, closely resembles a similar call of Horsfield's Bronze-Cuckoo except that it is roughly an octave lower and seems to be softer, but it does carry remarkably well through the scrub. I've heard Black-eared Cuckoos calling in many places in southern Australia and to me there is little variation - they all sound alike. Sometimes following the main downslurred whistling call a little variable whistle is added (038-185). Horsfield's Bronze-Cuckoo does something similar. I have also heard Black-eared Cuckoos emitting a call closely resembling the so called pipit-like chirrup given by Horsfield's Bronze-Cuckoos and I do have a recording but I can't be sure which species actually gave the call - they were both present at the time.