"Put a rock band in your mouth, along with a dab of toothpaste, with Tooth Tunes, a $10 musical toothbrush from Tiger Electronics, a division of Hasbro. The theory is that two minutes of brushing is needed to give teeth a proper cleaning. So the brush is really a kind of timer.
The feeling is a bit eerie. The sound is transferred through the brush tip, into the teeth, and right into the inner ear, so you feel the music. Because volume is related to pressure, you can turn up the volume by applying steady pressure to your teeth. Unfortunately, you can also hear better when not brushing, which children can soon learn."
- That Tune in Your Head Could Be Your Toothbrush