Petra, who used to post here but not any more, was trying some scientific effort on ear tones, but I suspect that what you propose is more interesting. But, you may want to track her down because she has a network of eartone sensitives. I hear them, but have zero reason to think they are related to quakes (OK, Petra's Parkfield prediction was pretty good and maybe one other...so maybe I'll leave room for interest in a scientific effort like you propose...although I won't participate (a dot now and then in the heartland probably won't mean anything).
Chris