Practical consideration for measuring airborne ultrasound measurement

When attempting to make meaningful measurements, airborne ultrasound in the 20 kHz to 100 kHz frequency range presents several significant challenges. These include source and sensor directivity, low signal-to-noise ratios, the inaudible nature of such sounds, and the lack of widespread literature on the subject. For each of these challenges, the practical impacts versus conventional acoustic measurements are identified and discussed. Solutions and suggestions are presented to allow reliable and repeatable measurements when presented with these challenges, including critical information to have prior to measurement, an assortment of techniques which may be employed when performing these measurements, and a brief overview of useful post-processing techniques. The concepts presented in this paper are illustrated using ultrasound measurements made in a vivarium.