The MK136 Stereo Super Ear electronic kit is a stereo audio amplifier that boosts sound 50 times allowing you to hear the most amazing sounds.
Not only great for the-hearing impaired (e.g. when watching TV) but also as a science project or low-cost gadget for listening to birds and wildlife, eavesdropping, safe-cracking, machine diagnostic tests, and whatever other amplifier project you have. Battery is not included.
Below is an example of how the Amplifier Kit works - caution to headphone wearers - the video does get quite loud about halfway through the demonstration.