Kids turn "teen repellent" sound into teacher-proof ringtone

Posted by Cory Doctorow, May 24, 2006 9:48 PM

Kids in the UK have co-opted an annoying noise sold to retailers as teenager-repellent and turned it into a ringtone. Mosquito is a high-pitched sound "audible only to teenagers" sold by Britain's Compound Security. It is sold to shopkeepers to use as a teenager repellent -- the idea is to play it loudly in and around shops and "chase away those annoying teenagers!!!" The kids have reportedly converted the high-pitched noise and turned it into a ringtone, which, being inaudible to grownups, can then be used to receive texts and calls in class without alerting teachers.

This is either a magnificent hoax or just plain magnificent -- either way, I love this Little Brother Watches Back parable. Schoolchildren have recorded the sound, which they named Teen Buzz, and spread it from phone to phone via text messages and Bluetooth technology. Now they can receive calls and texts during lessons without teachers having the faintest idea what is going on. A secondary school teacher in Cardiff said: 'All the kids were laughing about something, but I didn't know what. They know phones must be turned off during school. They could all hear somebody's phone ringing but I couldn't hear a thing.

Update: JS sez, "Considering that such high tones are virtually unattainable for the cell-phone loudspeakers I find the story highly suspect. Besides, the sound used as a ringtone would be compressed in some way (maybe not in the newer models, but would all kids have them?), further reducing the possibility that such high frequency content is preserved. I did little research and found this link where cell-phone audio capabilities are presented in detail. According to them the cell-phone's piezoelectric speaker caps its frequency response about at 10khz, while the Teen Buzz plays at 18khz to 20khz." I had similar doubts -- which suggests that these kids have done something even more subversive than creating an adult-proof ringtone: they've convinced adults that there's an inaudible sound that they can all hear.

Link to original article

Update 2: James sez, "I found this article about the mosquito system. It includes a link to an MP3 of the sound. I'm 18 and I can hear it, but neither my mom nor my step dad (both in their 50's) could distinguish the sound. It's worth noting that my step dad is a country music singer who has a very well trained ear. Since the sound carries over to MP3, and most new phones can play MP3s as ringtones, it would seem likely that students could use the mosquito sound as an adult proof ringer."

Update 3: Gregory sez, "Here's a data sheet for a piezoelectric speaker for cell phones, and shows frequency response measured out to 20kHz. The link that JS found did not say that frequencies above 10kHz were unattainable, but said "The frequency response of piezoelectric speakers is similar to small geometry moving coil speakers up to ~10 KHz bandwidth." As you can see by the data sheet at the URL listed above, small piezoelectric speakers are quite capable of being driven at frequencies above 20kHz. In fact, piezoelectric speakers are commonly used as tweeters in some sound systems; high frequencies are easy, it's the lows that give small speakers problems. A far more important question is the frequency response of the amplifiers that are driving the cell phone speakers. Amplifiers are typically band-limited to reduce noise and increase stability. What is the band limit for the phones in question?"

Update 3: Tony sez, "I've just had a look at 'Mosquito'. It's recorded at a low level, a sort of 'European siren', switching between two high tones at 2Hz. There are some giggles & rumble present (cells would probably not pass these audibly), but the high tones measure around 15,000 to 17,000 Hz. Interested geezers should pitch-shift the sound down an octave. That's exactly the same range as old TV flybacks used to emit ... which I *used* to be able to hear walking by someone's house."

Some great new technology articles

http://www.wired.com/gadgets/miscellaneous/news/2008/12/YE8_techbreaks

http://www.wired.com/software/webservices/news/2008/12/YE8_web

http://www.wired.com/politics/onlinerights/magazine/17-02/ff_obama?currentPage=all

http://blog.wired.com/business/2009/02/twitters-hackab.html

I'm still here

Sorry about the lack of posts recently, but I've been overseas in London and Paris, so I haven't posted much of late.

I have found heaps of great stuff to add to the blog soon, but I'm concentrating on finding a job before I use up my internets...

British ISPs restrict access to Wikipedia amid child pornography allegations

Potentially a sign of things to come here in Australia, if the government's proposed Internet Filtering plans go ahead. They've blocked access to the crappy poodle haired German cock rock band The Scorpions because they have an album called "Virgin Killer" which features a prepubescent girl on the front cover. I see that no one has called for Led Zeppelin's "Houses of the Holy" to be banned either...

It's a crap album, by a crap band and it was made in 1973, plenty of time in which to have had anyone connected with making/distributing/listening to or purchasing the album arrested. I think it's high time people to a long hard look at themselves before they try and break the Interweb Googletube. It's a series of tubes apparently and people can do things on it that are bad. Although there is no plans to filter/legislate content sent via peer to peer networks, email, torrenting or such, only the big bad "Internets".

http://en.wikinews.org/wiki/British_ISPs_restrict_access_to_Wikipedia_amid_child_pornography_allegations

http://en.wikinews.org/wiki/Wikimedia,_IWF_respond_to_block_of_Wikipedia_over_child_pornography_allegations

http://en.wikipedia.org/wiki/Virgin_Killer

No opt-out of filtered Internet

by Darren Pauli, Computerworld

Australians will be unable to opt-out of the government's pending Internet content filtering scheme, and will instead be placed on a watered-down blacklist, experts say. Under the government's $125.8 million Plan for Cyber-Safety, users can switch between two blacklists which block content inappropriate for children, and a separate list which blocks illegal material. Pundits say consumers have been lulled into believing the opt-out proviso would remove content filtering altogether.

The government will iron-out policy and implementation of the Internet content filtering software following an upcoming trial of the technology, according to the Department of Broadband, Communications and the Digital Economy. Department spokesman Tim Marshall said the filters will be mandatory for all Australians. “Labor’s plan for cyber-safety will require ISPs to offer a clean feed Internet service to all homes, schools and public Internet points accessible by children,” Marshall said. “The upcoming field pilot of ISP filtering technology will look at various aspects of filtering, including effectiveness, ease of circumvention, the impact on internet access speeds and cost.”Internet Service Providers (ISPs) contacted by Computerworld say blanket content filtering will cripple Internet speeds because the technology is not up to scratch. Online libertarians claim the blacklists could be expanded to censor material such as euthanasia, drugs and protest. Internode network engineer Mark Newton said many users falsely believe the opt-out proviso will remove content filtering. “Users can opt-out of the 'additional material' blacklist (referred to in a department press release , which is a list of things unsuitable for children, but there is no opt-out for 'illegal content'”, Newton said.

“That is the way the testing was formulated, the way the upcoming live trials will run, and the way the policy is framed; to believe otherwise is to believe that a government department would go to the lengths of declaring that some kind of Internet content is illegal, then allow an opt-out. “Illegal is illegal and if there is infrastructure in place to block it, then it will be required to be blocked — end of story.” Newton said advisers to Communications Minister Stephen Conroy have told ISPs that Internet content filtering will be mandatory for all users. The government reported it does not expected to prescribe which filtering technologies ISPs can use, and will only set blacklists of filtered content, supplied by the Australia Communications and Media Authority (ACMA).

EFA chair Dale Clapperton said in a previous article that Internet content filtering could lead to censorship of drugs, political dissident and other legal freedoms. “Once the public has allowed the system to be established, it is much easier to block other material,” Clapperton said. According to preliminary trials , the best Internet content filters would incorrectly block about 10,000 Web pages from one million.

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