USound MEMS loudspeakers can be evaluated in both acoustic domains: baffle and coupler conditions. 

How to measure USound MEMS loudspeakers

The object that is to be made invisible acoustically is placed at the centre of the experiment. The initial acoustic field is produced by the loudspeakers in the outer ring. The 228 control sensors in the central ring record this field and transmit the data to a computer. Subsequently, 36 control sources in the centre emit a secondary signal that augments the initial field in real-​time. (Photograph: ETH Zurich / Astrid Robertsson)

loudspeakers

How to measure USound MEMS loudspeakers

Acoustic illusions