Clearly, no one has noticed sounds of precursory breaking rock on the seismometers, whose frequency range only goes up to 100Hz or so. Seismometers are far more sensitive than your ears to the low-frequency vibrations in the Earth, by many orders of magnitude, that's just a fact.

Buy a microphone and record the sound. Figure out the pitch, look at the spectrum from the recording. A scientist would try to find objective evidence that there IS a sound in the air, then present their case and start the investigation of where it arose.

The biggest conceptual barrier to ear tones is that your ear is constantly deluged with sounds of all frequencies, so a tone from deep in the Earth would have to have awesome power to be readily heard, but if it is present, would be easily identified in a recording. It should also be much clearer in a quiet basement than outside, and perceptible to anyone with acute hearing, if it is really present.

Just trying to take a logical approach, and point out that it doesn't take a PhD to check out your idea. I can't say I am optimistic about the outcome.