Samsung Advanced Institute of Technology

Inspired by the human cochlea, we propose a directional sound sensor using a resonator array to overcome the limitations of existing directional microphones. The proposed sensor consists of multiple cantilevers that respond to different resonance frequencies and separately acquires signals to then combine them for sound sensing. The directionality of the cantilevers is bipolar because a signal proportional to the input sound’s pressure gradient is generated. We adopt multimode resonance to cover the wide frequency range of 8 kHz or less using few resonators. A wide-bandwidth (low-quality-factor) trenched cantilever resembling is used to obtain a flat frequency response. Bidirectional sound sensors are tapered to achieve acoustic beamforming by simple signal processing. The directional characteristics can be easily changed according to the weighted sum of the signals acquired from a pair of sensors. We demonstrate that ambient noise can be effectively suppressed through beamforming to acquire the desired signal using the proposed sensor.