According to the American College of Obstetrics and Gynecology, Ultrasound is energy in the form of sound waves. During an ultrasound exam, a transducer sends sound waves through the body. The sound waves come into contact with tissues, body fluids, and bones. The waves then bounce back, like echoes. The transducer receives these echoes, which are turned into images. The images can be viewed as pictures on a video screen.