A system and method of processing a sound signal. The method of processing a sound signal that includes the following steps: Synchronous reception of an input sound signal (Sinput) of N microphones, N being a natural number greater than or equal to three; Encoding of the input sound signal (Sinput) in a data format (D) of sound, the encoding including a sub-step of transforming the input signal into an ambisonic format of order R, R being a natural number greater than or equal to one, the sub-step of transformation into an ambisonic format is carried out by a Fast Fourier Transform, a matrix multiplication, an Inverse Fast Fourier Transform and by a band pass filter; and Return of an output sound signal (Soutput) by digital processing of the sound data (D).