Listen through walls with the high-tech spy stethoscope

We’ve all seen this in movies: Spies and private detectives using special devices to listen through walls. A few weeks ago, I posted about a Laser Espionage Microphone, and today, I’ll show you how you can make a high-tech spy stethoscope for under $25. All you need is:

• A cheap stethoscope
• A pair of multimedia microphones