Patent ID: 7587056

Claim:
A small array microphone apparatus, comprising: first and second omni-directional microphones respectively converting sound from a desired near-end talker into first and second signals, wherein the second and first omni-directional microphones and the desired near-end talker are arranged in a line; a microphone calibration unit receiving the first and second signals, calibrating on gain, and correspondingly outputting first and second calibration signals; and a directional microphone forming unit receiving the first and second calibration signals to output a first directional microphone signal with a predefined directivity according to a control signal and a second directional microphone signal with a fixed directivity for noise detections, further comprises: a first phase adjustment unit shifting the first calibration signal a first phase according to the control signal to generate a first shifted signal, the first phase being a first value for compensating sound propagation from the first omni-directional microphone to the second omni-directional microphone when the environmental noise power is below the predefined threshold, the first phase being less than the first value when the environmental noise power exceeds the predefined threshold; a second phase adjustment unit shifting the second calibration signal a second phase according to the control signal to generate a second shifted signal, wherein the second phase is 180° when the environmental noise power is below the predefined threshold, or 0° when the environmental noise power exceeds the predefined threshold; a third phase adjustment unit shifting the second calibration signal a fixed phase to generate a third signal; a first subtractor subtracting the second shifted signal from the first shifted signal to generate the first directional microphone signal; and a second subtractor subtracting the third signal from the first shifted signal to generate the second directional microphone signal wherein determination of the control signal is based on whether environmental noise power generated by an environmental detection unit exceeds a predefined threshold.