Stereo Separation and Directional Suppression with Omni-Directional Microphones

A system for stereo separation and directional suppression, the system comprising:

• at least one processor;
• and
• a memory communicatively coupled with the at least one processor, the memory storing instructions, which when executed by the at least one processor, perform a method comprising:
• receiving at least a first audio signal and a second audio signal, the first audio signal representing sound captured by a first microphone associated with a first location and the second audio signal representing sound captured by a second microphone associated with a second location, the first microphone and the second microphone comprising omnidirectional microphones of a mobile device, the distance between the first microphone and the second microphone being limited by the size of the mobile device;
• generating a first channel signal of a stereo audio signal by forming, based on the first audio signal and the second audio signal, a first beam at the first location;
• and
• generating a second channel signal of the stereo audio signal by forming, based on the first audio signal and the second audio signal, a second beam at the second location,
• wherein forming one or both of the first beam and the second beam includes:
• attenuating the first audio signal by a first attenuation factor;
• subtracting the attenuated first audio signal from the second audio signal to produce a first summed signal;
• attenuating the first summed signal by a second attenuation factor;
• and
• subtracting the attenuated first summed signal from the first audio signal to produce a second summed signal.

A non-transitory computer-readable storage medium having embodied thereon instructions, which when executed by at least one processor, perform steps of a method for stereo separation and directional suppression, the method comprising:

• receiving at least a first audio signal and a-second audio signal, the first audio signal representing sound captured by a first microphone associated with a first location and the second audio signal representing sound captured by a second microphone associated with a second location, the first microphone and the second microphone comprising omnidirectional microphones of a mobile device, the distance between the first microphone and the second microphone being limited by the size of the mobile device;
• generating a first channel signal of a stereo audio signal by forming, based on the first audio signal and the second audio signal, a first beam at the first location;
• and
• generating a second channel signal of the stereo audio signal by forming, based on the first audio signal and the second audio signal, a second beam at the second location,
• wherein forming one or both of the first beam and the second beam includes:
• attenuating the first audio signal by a first attenuation factor;
• subtracting the attenuated first audio signal from the second audio signal to produce a first summed signal;
• attenuating the first summed signal by a second attenuation factor;
• and
• subtracting the attenuated first summed signal from the first audio signal to produce a second summed signal.