Hi Petra:

Interesting report. I've a few Q's and comments.

What city are you in/nearby nowadays anyway ?

Do you think eartone frequency (also) indicates the magnitude of the quake versus distance ?

As far as distance, it seems it would be desirable to match the time of the eartone to perhaps a ULF/ELF spike in an instrument somewhere in order to try and figure the time of the "eartone cause" event and where it might be "sourced"...(and from that get the distance to the "source location"....). Of course, if it's an x-ray flux event then you could get a time (but not a location per se).

Couldn't two different quake precursor eartones both have the same duration but yet be located very far away from each other? Just a thought....

Also, perhaps you could identify the frequency you are hearing (see link below on free tone generator...). So far we've got 3000, ~5000-6000, and 7000 cps (Hz) as what is being heard....
(and some mid-C's (?) but I don't know the frequency exactly....)

Keep chipping away at it...

• EQF's tone frequency message/free tone generator msg