(I'm new to all this so please forgive me. This past week I've been trying to see if there is any correlation to tones I sometimes hear.)

As I think I understand it, tones usually derive from shifting prior to an earthquake? Maybe I'm wrong about that.

I was wondering if that is purely the case does that mean that there are no tools/equipment to measure sound in that frequency? Or are tones not a pure matter of auditory frequency but rather a combination of factors? Or maybe that the location of the monitoring device would be too difficult to decide?