How Does an Ultrasound Works? Ultrasound waves are produced by a transducer, which can both emit ultrasound waves, as well as to detect the ultrasound echoes reflected back. In most cases, the active elements in ultrasound transducers are made of special ceramic crystal materials called piezoelectrics. These materials can produce sound waves when an electric field is applied to them, but can also work in reverse, producing an electric field when a sound wave hits them. When used in an ultrasound