Youth Ring Tone

Some students are using a new ring tone to get messages in class, and many teachers can't even hear the ring.

The ring tone is too high-pitched to be heard by most adults.

With it, high schoolers can get text message alerts without the teacher knowing.

The phenomenon is known as aging ear -- a loss of the ability to hear higher-frequency sounds.

It happens to many people as they get older.

One New York teacher says a colleague played the ring for a classroom of first-graders.

All of the kids could hear it, while the adults couldn't hear anything.

The ring tone is a spin-off of technology that was originally meant to repel teens.

A security company developed the tone to help stores annoy youths loitering in front of their stores while leaving adults unaffected.