"It's because the sounds of the heart are very, very subtle," Meyer said. "It's kind of like a guitar, an old guitar. There may be newer, better models, but you know the sound that those strings make.

Playing doctor and nurse used to be so affordable as a kid. Nowadays, you need to fork out $69.99 for an iPhone app, and $279.99 for an additional stethoscope. Still, you can’t put a price on saving ...