The problem with using ear tones to forecast earthquakes is that so far humans seem to be the only known 'antennas' that receive them (or that can describe and record them). If a tone heard from varied locations differs enough so each individual must interpret it, the tones' usefulness exists only while that person lives or has patience to keep a written record of tones. So shouldn't the most important aspects of studying tones be to identify their source and discover how the brain interprets them as sound, and then to create non-human antennas that can receive them?
Mary C.