A tiny Welsh company whose high-pitched alarm for repelling yobs spawned a mobile ringtone teachers couldn't hear is set to hit the big time by selling an official version of the sneaky sound across the world.
Merthyr Tydfil-based Compound Security, which has just two employees, said experts believed its "Mosquitotone" would be bigger than the Crazy Frog, the infuriating ringtone which quickly became a global phenomenon.
The latest craze began earlier this year when a Scandinavian teenager developed an earsplitting high frequency sound into a ringtone.
It soon swept schools in the UK as pupils used it to exchange text messages in class undetected.
The idea was inspired by Compound Security's Mosquito alarm, based on the fact that most adults gradually lose the ability to hear high-pitched sounds and designed to stop louts loitering around shopping centres without upsetting grown-up customers.
Now, with the original version known as "Teen Buzz" already having hit the US, the company has developed its own 17 kilohertz version of the ringtone.
It went on sale in the UK for £3 on Friday, is available in the US from today and should be on sale in most countries around the world by the beginning of next week, marketing manager Simon Morris said.
In about 10 days a £500,000 TV and radio advertising campaign will begin.
The company is also considering producing melodic ringtones at a high pitch.
"It's just mindblowing," Mr Morris said.
"We're gobsmacked by it. And there's a huge scope to expand it.
"It seems to be popular with teenagers because it's one in the eye for the authorities and rules. It's sticking it to the man."
He said he did not believe there was any moral problem with the product, and the company was satisfied it could not be used for bullying.
"It's a bit of harmless fun really, isn't it?" Mr Morris said.
"If kids want to use their mobile when they shouldn't be they can already set them to vibrate or put them on silent, so it's not going to make any difference.
"Teachers we've spoken to say it's a bit of a giggle."
So far about 1,000 people have bought the ringtone in the UK.
"Experts we've spoken to in the industry say it's going to be bigger than the Crazy Frog," Mr Morris added.
He said he and managing director Howard Stapleton, who only launched the Mosquito alarm in December, had thought about doing a ringtone but did not think there would be a market for it.
The New York Times reported that schools in the city were buzzing with the original version of the ringtone, which sounds at a constant 14.4 kilohertz frequency.
"When I heard about it I didn't believe it at first," technology teacher Donna Lewis, from the Trinity School in Manhattan, told the newspaper.
"But one of the kids gave me a copy, and I sent it to a colleague.
"She played it for her first graders. All of them could hear it, and neither she nor I could."
A condition called presbycusis, or ageing ear, means that by the time most people reach the age of 25, they cannot hear much above a frequency of 13 or 14 kilohertz.