"Seeing with sound", the bat principle learnt from "listening" to nature

The bat finds its way around by using ultrasound waves in a frequency range of 10 to 120 KHz. It emits short pulses and picks up the sound reflected by obstacles. In this way, it detects all the obstacles in its path.
For the acoustic microscope, "obstacles" are defects in materials (materials that you might use), even those the eye does not see. Our "ear", the acoustic microscope, "hears" these defects, however, and makes them visible to the eye.
The acoustic microscope works the same way as a bat - although its frequency range is significantly higher.
 

The advantages of the Acoustic Microscope