Ring tones only a dog could love?

Seems high school students are going to great wave-lengths these days to communicate in the classroom without the teacher knowing.

A high-pitched sound developed in Britain to deter teen loitering and inaudible to most adults has invaded US classrooms where youngsters are using it in their cell phones to communicate without their teacher's knowledge.

The ring-tone, know as "Teen Buzz," allows students to surreptitiously exchange text messages unbeknownst to teachers whose older ears cannot detect the sound. ...

"Because the range of hearing varies greatly in individuals, it is possible that the teachers who do not hear this ring tone have never been able to hear up to the 17,000 range," said Stanton Jones, an audiologist at the St. Louis University School of Medicine. "Or age-related hearing loss may make the tone undetectable."

Children can hear high pitches. "Age-related hearing loss, or presbycusis, begins around age 35 with the highest pitches being lost first," Jones said.

There is, of course, an antidote to this new caper.

It's called an Audio Frequence Analyzer, and several companies offer quite affordable versions, including some that are software based. Teacher may not hear you, but she might be tuning in to your frequency, Kenneth, via her desktop. Or with this: