Seeing the heart with sound
Ultrasound-based echocardiograms yield ultra images of the heart.
Silent sound waves don't seem like they'd be much use. They are, though. They're the force behind submarine trackers and fish finders. In medicine, they give expectant parents a first look at their developing baby, and let doctors peer into the heart. An echocardiogram, which uses these sound waves, creates images with more detail than an x-ray but without any radiation exposure. It can also create real-time videos that show the heart in action.