There are many solutions based on the use of acoustic arrays, mainly microphone arrays. With the spread of sensor arrays, many studies on pattern synthesis techniques were developed to improve their performance. First, these techniques were based on varying sensor excitations (amplitude and phase) while keeping the sensors uniformly distributed. Next, techniques based on varying sensor positions, either following certain rules (aperiodic arrays) or randomly, with uniform excitations, were developed, and then algorithms that simultaneously optimize excitations and sensor positions emerged.
Digital microphones based on MEMS (Micro Electro-Mechanical Systems) technology include a microphone, a signal conditioner and an acquisition device built into the chip itself. This technology considerably reduces system costs, as well as the space occupied by the system, making it feasible to build arrays with hundreds or even thousands of sensors.
