The periodic configuration of energy produced by sound having a frequency greater than 30,000 Hz. ... (05 Mar 2000) ... 
waves similar to sonic waves but of such high frequency (20,000 hertz or higher) that the human ear does not perceive them as sound; see ultrasonics.
Type: Term Definitions: 1. the periodic configuration of energy produced by sound having a frequency greater than 30,000 Hz.
Waves of ultrasonic frequency. They include longitudinal, transverse, surface, and standing waves.
Waves of ultrasonic frequency. They include longitudinal, transverse, surface, and standing waves.