The two abstracts document beyond question that the Parkfield mainshock did not show anomalous EM precursors, in particular of the flavor claimed to have been recorded for the Loma Prieta earthquake.

If ear tones are claimed to arise from something other than vibrations or this frequency band of electromagnetic waves, which have been ruled out as short-term precursors to the Parkfield earthquake with instruments far, far more sensitive than the human ear, perhaps you could be more specific. Karma? Telepathy? Planetary alignment? What have you in mind?