Musical Toothbrush

Toy company Hasbro is rolling out a toothbrush that plays music through kid’s teeth as they brush. If I understand this right, you can only hear the music through your teeth in your head and not in your ears? Is that safe? Sounds like it could be annoying.

When the user pushes a button on the manual toothbrush, it "plays" a song. As the bristles are brushed across the teeth, they send sound waves through them so that the user hears the song in his or her head.