Performance evaluation of acoustical array by combining microphones and piezoelectric devices

An acoustical array by combining microphones and piezoelectric devices is a kind of acoustical sensor fusion to reduce the internal noise coming from the inside of the system such as machines, vehicles and robots. It can reduce the internal noise effectively, while it is difficult to reduce the internal noise by employing the conventional microphone array and blind source separation (BSS) algorithms such as ICA and sparseness approach because the internal noise is extremely close to the microphone and not always stationary, statistically independent and sparse. However, the performance difference between the conventional microphone array and the acoustical array to combine microphones and piezoelectric devices has not been evaluated yet. In this paper, we evaluate the performance of the acoustical array with microphones and piezoelectric devices and show the different features compared to the conventional microphone array.