Design and analysis of miniature and three tiered B-format microphones manufactured using 3D printing

This paper describes miniature and three-tiered B-format microphone array designs for accurate sound source localisation that are manufactured using 3D printing and MEMs devices. The implications of pressure gradient resolution reduction in spatial-temporal sampling on the accuracy of Direction of Arrival (DOA) estimation is analysed through simulated room impulse response measurements and characterized by the directional signal to noise ratio. It is shown how the capsule spacing can be optimally chosen based on microphone capsule sensitivity and the required DOA accuracy. Through this method a new three tiered B-format microphone array is proposed, where each tier optimally records 3D sound for a given frequency sub-band to achieve highly accurate DOA estimation for the full audible frequency range of 50 Hz to 20 kHz.