Medical scientists can use sound waves to see inside the body.
Pulses of sound are transmitted into the body and the resulting echoes are recorded. One common use of this technology is to picture the fetus inside the mother's womb. Another use is to picture the heart's size, shape, and movement. Echocardiography is the process of mapping the heart through echoes. The pulses are sent into the chest and the high-frequency sound waves bounce off of the heart's walls and valves.