Tone deaf teachers

In order to evade rules against using cell-phones in class, some students are downloading a ring tone off the Internet that is too high-pitched to be heard by most adults. The tone allows high school students to receive text message alerts on their cell phones without the teacher knowing. A teacher in New York City says her colleague played the ring for a classroom of first-graders — and all of them could hear it, while the adults couldn't hear anything.