DUAL OMNIDIRECTIONAL MICROPHONE ARRAY (DOMA)
A dual omnidirectional microphone array noise suppression is described. Compared to conventional arrays and algorithms, which seek to reduce noise by nulling out noise sources, the array of an embodiment is used to form two distinct virtual directional microphones which are configured to have very similar noise responses and very dissimilar speech responses. The only null formed is one used to remove the speech of the user from V 2 . The two virtual microphones may be paired with an adaptive filter algorithm and VAD algorithm to significantly reduce the noise without distorting the speech, significantly improving the SNR of the desired speech over conventional noise suppression systems.
1 . A device comprising:
a headset including at least one loudspeaker, wherein the headset attaches to a region of a human head, the headset including a first area and a second area at which to dispose a first physical microphone and a second physical microphone, respectively, the first physical microphone being disposed at least an intra-microphone distance from the second physical microphone, the intra-microphone distance being less than a dimension of the headset;
a microphone array connected to the headset, the microphone array including the first physical microphone outputting a first microphone signal and the second physical microphone outputting a second microphone signal, and the first physical microphone and the second physical microphone forming an axis of the microphone array; and
a processing component coupled to the microphone array and configured to generate a virtual microphone array comprising a first virtual microphone and a second virtual microphone of which at least one is based on the intra-microphone distance, the first virtual microphone comprising a first combination of the first microphone signal and the second microphone signal, the second virtual microphone comprising a second combination of the first microphone signal and the second microphone signal, wherein the second combination is different from the first combination, wherein the first virtual microphone and the second virtual microphone have substantially similar responses to noise and substantially dissimilar responses to speech, and wherein the second virtual microphone is configured to generate an output signal in response to a speech signal received at the microphone array, the output signal in response to the speech signal being zero when the speech signal is received substantially along the axis of the microphone array, and to generate an output signal in response to a noise signal received at the microphone array, the output signal in response to the noise signal not being zero when the noise signal is received substantially along the axis of the microphone array.