Three problems with ear tones are stated by Chris, and a fourth I add:
(1) �gnever heard by more than one person at the same time�c�h[mechanism of perception]. This would seem to indicate that even if an external perceived signal is involved, various internal states determine perception. Big problem.
(2) �geartones are emitted from faults? No�h [mechanism of origin] Of course, Chris has mentioned electrophonic transduction, which I also think is the likely explanation. EM radiation is emitted from faults, and this (not sound emissions) could be the source of some or all ear tones.
(3) �gthe length of the eartone is�crelated to the distance to the earthquake�c?�h [perception/location relationship] The 37.5 miles of distance calculated for each second of hearing a tone seems to be a formula based on observations made by Petra. I suppose a maximum ear tone would be between 5-6 minutes, or twice that if the distance is all the way around the world.
(4) If EM radiation associated with faults is the origin, one problem is that such radiation has not been explained. There are various hypotheses, including piezo-electric effects, fluid changes in rock, etc. Moreover, correlation with earthquakes has been controversial. Therefore, you are without explanations at both ends: origin and perception.

Random comment: just because more than one person does not hear a tone, does not mean it might be �gsome random event in the brain that has nothing to do with external stuff.�h The word random seems to have been inserted to mean �gsome internal event the origin of which is not understood.�h It is not necessary for the internal event to be random, to make it unrelated to faults or other external things. I doubt if you could ever show that an event in the brain, or anywhere, occurred randomly. In that sense, there are no events that can be said to be random. Leave random thoughts to cryptologists and mathematicians.

John wrote, �gIf it comes at 40 miles/s or any other sub-lightspeed velocity, that is not EM radiation.�h I think he has misunderstood the �g37.5 miles per second�h which was a method of calculation, not a speed. On another Board, I had suggested to Petra that this wording might be confusing (and by the way, please use kilometers, not miles!!) but if at this point in your discussion, John is still misunderstanding this point, I think communication between those debating is a very big and basic problem, maybe even dwarfing the four problems above.