This article reviews an acoustic technique for aerosol particle detection,
based on data obtained with a series of systematically designed experiments using acoustic transducers. The capabilities of detecting particles and particle concentration in a real-time manner are demonstrated. The phenomenon allowing such capability lies in the inability of particles to follow rapidly accelerating flows, resulting in vortex shedding and the associated pressure fluctuations. The simplicity and potential to miniaturize the acoustic transducer makes it an attractive alternative to the commercially available, and more costly, laser- or optics-based particle counters.