How are the ultrasonics deals with sound waves?

Ultrasonics, deals along with sound waves which pass a specified point at least 20,000 times per second. As ultrasonic waves vibrate very quickly, additional units also are used to shows their frequency. There kilohertz (kHz), for instance, can be used to measure sound waves vibrating at the certain rate of 1,000 times per second, as well as the unit megahertz (MHz) stands for a million vibrations per second. Several ultrasonic devices have been constructed that produce waves along with frequencies of more than a billion hertz.