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From Gakken's Sophisticated Science Kit for Adults, this replica kit uses the same technology that Thomas Edison used, replacing Edison's waxed pipe and stylus, the kit uses a plastic cup and a needle, but the end results are the same! You record your own voice on a plastic cup -- and play it back! Here's how it works, your voice vibrates the air minutely when it gets into the horn. Then the vibration is conducted to the needle and is translated into a wavy movement of the needle and carves a groove onto the cup.

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