Signal processing methods and systems for beam forming with microphone tolerance compensation

An apparatus for generating a directional output signal from sound received by at least two microphones arranged as microphone array, said apparatus comprising at least one processor adapted to perform:

• transforming analog-to-digital converted time-domain signals provided by respective ones of said at least two microphones into corresponding complex-valued frequency-domain microphone signals, the analog-to-digital converted time-domain signals representing respective sounds received by said at least two microphones, wherein each one of the corresponding complex-valued frequency-domain microphone signals has a frequency component value for each frequency component of a plurality of frequency components;
• and
• calculating, for each frequency component of the plurality of frequency components of the complex-valued frequency-domain microphone signal of at least one of said at least two microphones, a respective tolerance compensated frequency component value by multiplying the frequency component value of the complex-valued frequency-domain microphone signal of the at least one of said at least two microphones with a frequency-specific real-valued correction factor, wherein the frequency-specific real-valued correction factor compensates for at least a sensitivity deviation relative to a reference microphone within the microphone array or a combination of reference microphones w the microphone array.

One or more non-transitory computer-readable media having instructions stored thereon, the instructions for microphone tolerance compensation when generating a directional output signal from sound received by at least two microphones arranged as microphone array, and the instructions to cause one or more processors to perform operations comprising:

• transforming analog-to-digital converted time-domain signals provided by respective ones of said at least two microphones into corresponding complex-valued frequency-domain microphone signals, the analog-to-digital converted time-domain signals representing respective sounds received by said at least two microphones, wherein each one of the corresponding complex-valued frequency-domain microphone signals has a frequency component value for each frequency component of a plurality of frequency components;
• calculating, for each frequency component of the plurality of frequency components of the complex-valued frequency-domain microphone signal of at least one microphone of said at least two microphones, a respective tolerance compensated frequency component value by multiplying the frequency component value of the complex-valued frequency-domain microphone signal of said at least one of said at least two microphones with a frequency-specific real-valued correction factor, resulting in tolerance compensated frequency component values, wherein the frequency-specific real-valued correction factor compensates for at least a sensitivity deviation relative to a reference microphone within the microphone array or a combination of reference microphones within the microphone array;
• and
• forming a tolerance compensated complex-valued frequency-domain microphone signal from said tolerance compensated frequency component values for said plurality of frequency components.