A complete three-dimensional sound intensity sensor integrated on a single chip

Complete characterization of a sound field requires measurement of both sound pressure and particle velocity. In this paper, we present a three-dimensional acoustic particle velocity sensor chip. Furthermore, a sound pressure sensor was integrated on the same chip, enabling three-dimensional sound intensity measurements. The integration of multiple sensors on a single silicon chip results in highly reproducible sensors and a very small sensor-to-sensor distance allowing for accurate single-point measurements. The latter is demonstrated by measurement of the 3D particle velocity field of a very small (1 × 1 mm2) sound source.