A ring tone meant to fall on deaf ears

By Paul Vitello
The New York Times
Published: June 12, 2006, 7:33 AM PDT

In that old battle of the wills between young people and their keepers, the young have found a new weapon that could change the balance of power on the cell phone front: a ring tone that many adults cannot hear.

The technology, which relies on the fact that most adults gradually lose the ability to hear high-pitched sounds, was developed in Britain but has only recently spread to America--by Internet, of course.

Recently, in classes at Trinity and elsewhere, some students have begun testing the boundaries of their new technology. One place was Michelle Musorofiti's freshman honors math class at Roslyn High School on Long Island.

At Roslyn, as at most schools, cell phones must be turned off during class. But one morning last week, a high-pitched ring tone went off that set teeth on edge for anyone who could hear it. To the students' surprise, that group included their teacher.

"Whose cell phone is that?" Musorofiti demanded, demonstrating that at 28, her ears had not lost their sensitivity to strangely annoying, high-pitched though virtually inaudible tones.

"You can hear that?" one of them asked.

"Adults are not supposed to be able to hear that," said another, according to the teacher's account.

She had indeed heard that, Musorofiti said, adding, "Now turn it off."

The cell phone ring tone that she heard was the offshoot of an invention called the Mosquito, developed last year by a Welsh security company to annoy teenagers and gratify adults, not the other way around.

It was marketed as an ultrasonic teenager repellent, an ear-splitting 17-kilohertz buzzer designed to help shopkeepers disperse young people loitering in front of their stores while leaving adults unaffected.

The principle behind it is a biological reality that hearing experts refer to as presbycusis, or aging ear. While Miss Musorofiti is not likely to have it, most adults over 40 or 50 seem to have some symptoms, scientists say.

While most human communication takes place in a frequency range between 200 hertz and 8,000Hz (a hertz being the scientific unit of frequency equal to one cycle per second), most adults' ability to hear frequencies higher than that begins to deteriorate in early middle age.