Ringtone buzzes past adults
By Amberlee Sterling

People can't catch West Nile virus from this buzz, but the high-pitched frequency of the mosquito ringtone, designed to be heard only by children and teenagers, has spread quite a commotion across the world.

Compound Security Systems Ltd., a Welsh security company, originally designed the tone to keep teenagers from loitering outside of stores while allowing adults, who usually cannot hear it, to go about their shopping, according to the company's Web site.

A group of unknown, possibly Welsh teenagers or someone from Scandinavia turned the invention around to create a ringtone that only they could hear, making cell phones usable in classroom settings, according to The Washington Post.

When Howard Stapleton, inventor of the mosquito ringtone, realized he was losing the opportunity for financial gain, he decided to market his own ringtone, according to timesonline.co.uk.

A link for the "official mosquitotone," which rings out at 17 kilohertz, can be found at compoundsecurity.co.uk.

Hertz is "the number of cycles of a sound wave in one second," according to the American Hearing Aid Associates Web site.

It is not a good idea for students to use the high pitched ringtone during class, said Amyn Amlani, audiologist and assistant professor of speech and hearing sciences at NT.

"Number one, if you are in a classroom and the ringtone goes off, which most other people can't hear, then you're not concentrating on the things that you are expected to learn," he said. "The second thing is, when the ringtone goes off and you start responding to a text message, the people around you become disturbed and their ability to concentrate on the task at hand is also reduced."

Ability to hear high frequency sound, like the mosquito ringtone, reduces at age 30 due to the natural aging process, Amlani said.

Children under eight can hear it best because the natural aging process has not begun and the ear canal or ear tube is short because their head is small, Amlani said.

"As the head grows and the ear canal becomes longer, so as the tube becomes longer the resident peak moves from a higher frequency to a lower frequency," he said. "So for children who are roughly eight years of age and younger, their ability to pick up this sound and have the outer ear amplify it is greater than someone who has an adult sized ear."

Other factors beside the natural aging process play into whether or not someone can hear the mosquito ringtone, Amlani said.

Hearing the sound depends on the cell phone's receiver, he said. Also, diffraction occurs with high frequency sounds.

"Because they have less intensity and their wavelengths are shorter, they don't travel as far in distance," Amlani said. "Because of that, the direction from which the sound is coming is hugely important."