A New Buzz

  Chalk one up for the teenagers.

  Last year, a British shopkeeper, pushed to his wit’s end by loitering and unruly teens, enlisted the help of a firm called Compound Security Systems to develop a device that would ward off the hoods.  The result was a little black box called The Mosquito, mounted outside of his shop, which generates a high-pitched hum that only teens can hear—and it drives them crazy.

  It may sound like science fiction, but the technology is based on a common form of hearing loss called presbycusis, which is age-related.  “The human ear is responsive to a range of pitches,” says Vic Gladstone, an audiologist from the American Speech-Language-Hearing Association, “and that range gets smaller in the higher pitches with age.”  In other words, the older we get, the harder it is to hear sounds at higher frequencies.  The tone generated by The Mosquito is about 17 kilohertz, which is inaudible to most adults over 25, but very audible to almost all teenagers.  And, quite frankly, it drives them up a wall. 

  “Around 20 teenagers aged 16-plus would often hang around outside the shop, creating a lot of noise,” says Sue Oates, who manages a shop in the UK that has recently employed a Mosquito.  “Customers felt intimidated when they came down in the evening.  It was very intimidating for them.  But since the Mosquito has been there the number of youths has dropped dramatically so staff and customers feel a lot safer.”

  The sound is similar to the high-pitched hum given off by an old television set when the volume is turned all the way down, or to the hum of old fluorescent light fixtures.  At high volumes, it’s enough to move the kids along.

  But teenagers are not to be outwitted by technology.  About a month ago, a group of clever teens realized that they could capture this sound with their cell phones and use it as a ringtone—a ringtone that only they can hear.  Dubbed the “Teen Buzz” or “Mosquito Tone,” it’s already well on its way to becoming the highest-selling ringtone of the year.  Now teens can receive text messages in class, be alerted by an audible signal, and not get into trouble for it.  And among many teens, the sheer novelty of it has caused them to disregard the “vibrate” settings on their phones altogether.

  But there’s a catch.  Since presbycusis is caused, in part, by exposure to loud sounds, its onset varies and affects every person differently.  So while most people over 25 cannot hear the tone at 17 KHz, others can hear it into their thirties.

  I’m 28, and I can hear the Mosquito just fine.  My boss at the radio station is 30, and he can hear it too.  I played it for another DJ, a woman in her early 50’s, and she couldn’t hear a thing.  But there is a gray area, from 25 to 35, and many teachers fall within this age range. 

  A touch of irony:  Howard Stapleton, who invented The Mosquito for Compound Security Systems, is 39.  He has never heard the tone that is making him millions, and he never will.

  Can you hear it?  A little surfing should be able to net you a sample of the tone.  In the U.S., the ringtone’s available online at www.fork.com.

-From Pulse
  June 22, 2006