Audio processing

A server, comprising a processor and memory, the memory containing instructions which cause the processor to:

• receive a plurality of audio signals;
• derive a plurality of time-frequency signals from the received audio signals, indexed by frequency, and for each of the time-frequency signals:
• determine in-beam components of the received audio signals;
• and
• perform post-processing of the received audio signals, the post-processing comprising:
• computing a reference level based on the received audio signals;
• computing an in-beam level based on the determined in-beam components of the received audio-signals;
• computing a post-processing gain to be applied to the in-beam components from the reference level and in-beam level;
• and
• applying the post-processing gain to the in-beam components, wherein the in-beam level is used to compute a covariance, c(t,f), between the determined in-beam components of the received audio signals and the received audio signals and wherein the computed covariance is used to compute the post-processing gain.

A video-conferencing endpoint, comprising:

• a plurality of microphones;
• a video camera;
• a processor;
• and
• memory, wherein the memory contains machine executable instructions which, when executed on the processor cause the processor to:
• receive respective audio signals from each microphone;
• derive a plurality of time-frequency signals from the received audio signals, indexed by frequency, and for each of the time-frequency signals:
• determine in-beam components of the received audio signals;
• and
• perform post-processing of the received audio signals, the post-processing comprising:
• computing a reference level based on the received audio signals;
• computing an in-beam level based on the determined in-beam components of the received audio signals;
• computing a post-processing gain to be applied to the in-beam components from the reference level and in-beam level;
• and
• applying the post-processing gain to the in-beam components, wherein the in-beam level is used to compute a covariance, c(t,f), between the determined in-beam components of the received audio signals and the received audio signals and wherein the computed covariance is used to compute the post-processing gain.