Patent ID: 9354335
Filing Date: 2016-05-31
CPC Classification: G01V

Claim Text:
1. A method of processing an audio signal, comprising: receiving the audio signal, the audio signal comprising an audio signal detected by a geophone placed in a well for monitoring hydraulic fracturing, wherein the audio signal is received in accordance with a sampling rate and has a cutoff frequency defined by the sampling rate; compressing a dynamic amplitude range of the audio signal in accordance with a predefined ratio; modifying the compressed audio signal using a nonlinear distortion operator to generate a modified audio signal, wherein the modified audio signal has high frequency audible components not present in the received audio signal, comprising audible components introduced by the nonlinear distortion operator in a predefined frequency range above the cutoff frequency defined by the sampling rate of the received audio signal; and sending the modified audio signal to an output configured for connection to a stereo or multi-channel speaker system, wherein a user of the stereo or multi-channel speaker system is able to determine the locations of the microseismic events from listening to the modified audio signals.