No caves near Santa Cruz, Ca. as far as I know. Doubt there are any in Santa Rosa (Petra) either. I used to live in Carlsbad, NM. I don't remember if I heard ear tones then (1979) because I wasn't paying attention to them as much as I do now. I, too, was awakened by one a few days ago. I've also been sick and needing more sleep, so that is really saying something. I would liken it to Petra's "Deep, dark and ugly."

However, unlike most who hear tones, my right ear is for north, not south of me. I haven't done the math, but my guess is that if ear tones are indeed associated with earthquakes, I may be hearing something off the coast of WA or as far north as Alaska.

Petra, what is the time span between your hearing a tone and the event associated with it?

Cathryn