A Comparative Study on Using Phased or Timed Arrays in Audio Surveillance Applications

Array processing techniques are widely used in audio applications, especially in audio surveillance systems, where one of the tasks is the scan of the surroundings and the detection of acoustic sources. The array sensors sample the sound field in space, the same way an analog-to-digital converter samples sound in time. Correspondingly, the Nyquist criterion should be applied in the space domain in order to avoid aliasing artifacts. However, the audio spectrum is wide and reducing the sensor dimensions providing the correct reconstruction for all higher audio frequencies can be problematic. In this paper, we propose a comparative study on the usage of phased array solutions and the timed array counterpart.