When a person sustains an injury to the spinal cord, the normal communication between the brain and the spinal circuits below ...

A standard electret microphone can detect sub-audio "sounds" when some simple equalization circuitry is added.

Abstract: This article focused on investigating the resonance frequency of piezoelectric transducers (PZTs) and the impact of different compensation methods on the performance of ultrasonic wireless .

Shien-Ming Wu School of Intelligent Engineering, South China University of Technology, Guangzhou 510641, China ...

Not so, if you use a pair of specialised ultrasonic transducer arrays to move the air instead! (Video, embedded below) Three banks of thrusters provide a 180 degree steerable net force Details are ...