Here's a low-tech experiment that you can do on the cheap that will keep kids fascinated for hours.It's sad to say that the era of cassette decks is just about over. Replaced first by CDs and then by the purely digital form of music, those of us who grew up with the soothing hiss of magnetic tape in our Walkman headphones can't help but feel a little old. The upside of this is that tape decks are as cheap as the dickens now, and with two or more of them you can show your kid something really cool.
Borrow or yard sale a few cassette players - this can be a fun group activity with your neighbors, if you want to get them digging in their closets for old stereo equipment. Make sure at least one has a microphone - many portable ones have built-in microphones or a jack to plug one in. You'll also need a number of answering machine tapes - the kind used for outgoing messages. You can get them at Radio Shack or extremely cheap on the Internet. These tapes are a little different from ordinary cassettes in that they are constructed as a continuous loop - put them in a player and they'll run forever, repeating the same 30 seconds over and over again. Lastly, you'll need a stopwatch.
Take a blank answering machine tape, put it in the player with the microphone, and get a kid ready. Tell them to make any noise they want into the microphone when you say GO! Say it, hit Record, and start the stopwatch. Stop at 30 seconds (or however long the outgoing message tape is) and put the tape in another player. Hit Play and you've got a loop going. Do another tape with a different kid and repeat until you've built a glorious cacophony of pre-digital bliss.
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