Arduino Decibel Alarm for Noisy Kids

Background

My wife and I are night-owls but our children are early risers. We used to get up with them every morning, but have slowly trained them to do their morning routine by themselves. The only problem with this arrangement is when the kids decide to reenact "Lord of the Flies." They can get very noisy, interrupting my precious sleep. I get really cranky when I haven't had enough sleep. The kids are very responsive when I tell them to be quiet, but they quickly return to their activities and resume their loud volumes before I can drift back to happy land.

If my wife or me sits down with the kids and constantly reminds them to be quiet, then they do pretty well. But then only one of us gets to sleep (usually me). I just wish there was some kind of electronic babysitter that could tend the to the kids' volume during that hour between six and seven in the morning.

The Idea

Use an electret microphone on an Arduino to listen to the kids as they play. When their noise level goes too high then it will trigger a recorded message that will encourage the kids to be quiet.

This could be used in multiple ways. If noise a single, short noise spike is detected (like a shriek) then it could play a nice recording of Dad saying, "Remember to be quiet kiddies." If the volume is steadily rising it could say, "Hey, your getting out of control, time to do something more quiet like reading a book." Finally, if the volume stays steadily loud it could play something truly frightening.

Progress

11/27/2014 - I've got an Arduino, and an SD card kit that can be used to play MP3 files. I just need to find a suitable speaker and microphone. Instead of a speaker I've got an FM transmitter that can be connected to the Arduino and I could turn on the radio to a blank channel. I think a speaker would be easier, and more portable.