Device and method for capturing and processing a three-dimensional acoustic field

A method for encoding a three-dimensional acoustic field, comprising:

• encoding an acoustic field captured by microphone buttons of a capture device that comprises a first microphone button with a substantially cardioid directivity and a second microphone button with a substantially cardioid directivity, placed in a Cartesian coordinate system XYZ, the first button and the second button not coinciding and being positioned along axis X on either side of plane YZ and at equal distances from said plane YZ, first and second main axes of said buttons being orthogonal to the axis X and coplanar to one another, the first main axis oriented toward a front of the first microphone button forming an angle alook with the axis X and an angle elook with plane XY, the second main axis oriented toward a front of the second microphone button forming an angle of π+alook with the axis X and an angle elook with the plane XY, by
• receiving a first signal from the first microphone button and a second signal from the second microphone button,
• (a) performing a time-to-frequency transform of the first signal and the second signal to obtain a first frequency signal and a second frequency signal,
• (b) receiving said first frequency signal and said second frequency signal and performing, for a frequency from among a plurality of frequencies, a panorama measurement,
• (c) receiving said first frequency signal and said second frequency signal and performing, for a frequency from among a plurality of frequencies, a phase difference measurement,
• (d) determining the direction of origin by receiving said panorama measurement from (b) and said phase difference measurement from (c), and determining, for a frequency from among a plurality of frequencies, an azimuth angle and an elevation angle of the direction of origin, and
• (e) receiving said azimuth and elevation angles of (d), and determining, for a frequency from among a plurality of frequencies, a magnitude and a phase.

A method for encoding a three-dimensional acoustic field, comprising:

• encoding an acoustic field captured by microphone buttons of a capture device that comprises a first microphone button and a second microphone button, placed in a Cartesian coordinate system XYZ, the first button and the second button not coinciding and being positioned along axis X on either side of plane YZ and at equal distances from said plane YZ, wherein:
• the first microphone button has a substantially omnidirectional directivity,
• the second microphone button has a substantially cardioid directivity,
• the first microphone button is situated in plane XY, and
• a main axis oriented toward a front of the second microphone button is in the plane XY and forms an angle alook=π/2 with the axis X, by:
• receiving a first signal from the first microphone button and a second signal from the second microphone button;
• (a) performing time-to-frequency transforms of the first signal and the second signal to obtain a first frequency signal and a second frequency signal,
• (b) performing, for a frequency from among a plurality of frequencies, a magnitude ratio measurement of said first and second frequency signals,
• (c) performing, for a frequency from among a plurality of frequencies, a phase difference measurement,
• (d) receiving said magnitude ratio measurement from (b) and said phase difference measurement from (c), and determining, for a frequency from among a plurality of frequencies, an azimuth angle and an elevation angle of a direction of origin, and
• (e) receiving said azimuth and elevation angles of (d), and determining, for a frequency from among a plurality of frequencies, a magnitude and a phase.