The Mosquito

The Mosquito or Mosquito alarm is a machine used to deter loitering by emitting sound at high frequency. In some versions, it is intentionally tuned to be heard primarily by younger people. Nicknamed "Mosquito" for the buzzing sound it plays, the device is marketed as a safety and security tool for preventing youths from congregating in specific areas.

The latest version of the device.. launched late in 2008, has two frequency settings, one of approximately 17.4 kHz that can generally be heard only by young people, and another at 8 kHz that can be heard by most people. The maximum potential output sound pressure level is stated by the manufacturer to be 108 decibels (dB) (comparable in loudness to a live rock concert) and the manufacturer's product specification furthermore states that the sound can typically be heard by people below 25 years of age. The ability to hear high frequencies deteriorates in most humans with age (a condition known as presbycusis), typically observable by the age of 18.

History

The Mosquito machine was invented and patented by Howard Stapleton in 2005, and was originally tested in Barry, Wales, where it was successful in reducing teenagers loitering near a grocery store. The idea was born after he was irritated by a factory noise when he was a child. The push to create the product was when Stapleton's 17-year-old daughter went to the store to buy milk and was harassed by a group of 12- to 15-year-olds. Using his children as test subjects, he determined the frequency of "The Mosquito".