Patent Document ID: 9491543
Application ID: 14616923
Patent Status: 1

Claim One:
1. A method of improving quality of an audio signal in a voice communication system, the method comprising the steps of: (a) receiving one or more samples of the audio signal from a first microphone and a second microphone; (b) setting a propagation delay of ‘t’ samples between the first microphone and the second microphone; (c) subtracting delayed second microphone signal from the first microphone signal to obtain a first cardioid signal ‘x(n)’; (d) subtracting delayed first microphone signal from the second microphone signal to obtain a second cardioid signal ‘y(n)’; (e) filtering the second cardioid signal ‘y(n)’ to obtain a first output signal ‘a(n)’; (f) subtracting the first output signal a(n) from the first cardioid signal ‘x(n)’ to get a directional signal ‘z(n)’; (g) iteratively identifying speech regions and non-speech regions of the directional signal ‘z(n)’ for each sample of the audio signal received; and (h) filtering the signal ‘y(n)’ to obtain any residual noise signal that is left over in ‘z(n)’ and subtracting the residual noise from the directional signal ‘z(n)’, upon detecting any non-speech region thereby improving the quality of the audio signal.