Determination of the Sound Intensity Vector Field from Synchronized Sound Pressure Waveforms

Visualization of vector acoustic fields using sound intensity measurements is a very interesting field of acoustics and has numerous applications. Unfortunately, sound intensity measurement itself requires specialized measuring instruments (presure-presure (PP) or pressure-velocity (PU)-type probes). This article presents a simplified and low-cost method of sound intensity measurement based on sound pressure measurements made synchronously. This allows for the use of a single microphone and eliminates one of the main problems of the classical PP probe, which is the phase mismatch of two different microphones. The described method was used to visualize the vector acoustic field in front of an active loudspeaker. The results were compared qualitatively and quantitatively with measurements made with a commercial PU intensity probe. The results obtained showed that the proposed method has the same level of metrological accuracy.