Dunedin schools appear largely oblivious to the teenage fad of downloading a high-pitched ringtone to cellphones and then playing it in class to annoy fellow pupils and test teachers' hearing.
It is not surprising most principals and teachers do not know about it.
The "30,000hz" ringtone was inspired by "mosquito box" devices - such as those used by the Dunedin City Council in bad behaviour-prone retail areas - which emit an annoying high-pitched tone normally only audible to people under the age of 25.
The fad appears to have started earlier this year and seems to be particularly prevalent among 14 and 15-year-olds.
Hannah Edington (15), of Otago Girls High School (OGHS), said she had the ringtone on her phone "because everyone else had it".
She used it "mostly just to annoy" others.
About two-thirds of the pupils in her class had the ringtone, she said.
Roman Ruddell (15), of Kavanagh College, and Fergus Bevin-McCrimmon (15), of John McGlashan College, said it was used to annoy people rather than to receive texts or calls undetected.
"The teachers can't hear it," Roman said.
One teenager said she and several classmates had repeatedly set off the ringtone during a science class and when the teacher asked what the noise was, responded that it was leaky taps.
Year 11 and 12 Otago Boys High School (OBHS) pupils who did not want to be named told The Star the ringtone which they knew as "the mosquito" became popular among 14 and 15-year-olds earlier this year.
"They play it over and over to see if the teacher can hear it," one of the boys said.
"Our maths teacher can hear it but most others can't," another boy said.
Of six Dunedin high schools contacted by The Star only John McGlashan College principal Mike Corkery said he was aware of the fad.
Mr Corkery did not believe it was a serious problem.
"It's a dreadful thing that we get older and can't hear it," he said.
The school's policy on cellphone use was that they should not be used in class because it was rude.
"It's rude if you are texting when someone else is talking," Mr Corkery said.
OBHS rector Clive Rennie and OGHS principal Jan Anderson said pupils were allowed to have phones at school but they must be turned off during class.
Anyone found with a cellphone on at the wrong time would have it removed, Mrs Anderson said.
Kavanagh College principal Tracy O'Brien said while he had not heard of the issue it did not mean it was not happening.
"We will keep an eye on it," Mr O'Brien said.
