Having trouble with teens loitering in areas of concern or individuals of any age gathering in front of your building or place of business, and making people feel unsafe? The Mosquito alarm promises to resolve this problem using very high frequency sound to annoy teenagers who can typically hear the sound. The range of human hearing is estimated from 20Hz to 20,000 Hz (20KHz). This device can be set to 17KHz to disperse the teenage population or 8KHz to disperse people of any age from loitering in areas of concern. A range of manufacturer claims for products like this indicate that the high frequency tones can broadcast sound anywhere from 75dB to 95dB. It was recently placed outside of a busy metro rail station in Washington, DC with a variety of retail and entertainment businesses nearby. This area has become a popular hangout for teenagers, and recently the site of a brawl that left several metro rail passengers injured. (The alarm was subsequently removed after complaints of age discrimination.)
But beyond mere annoyance, can devices like the Mosquito alarm add to a growing concern: noise induced hearing loss (NIHL) among teens? Research published recently in the Journal of the American Medical Association (JAMA) showed an increase in teen hearing loss. The study showed that one in five U.S. adolescents 12 to 19 years old, approximately 6.5 million teens, had hearing loss in 2005-2006. Side effects such as severe headache were reported by pedestrians traveling to and from the Washington, DC metro rail station while the Mosquito alarm was in place. Due to the limited technical data disclosed about these devices, the potential negative impact on hearing and other health effects are unknown at the present time. There is currently no federal regulation for the use of this type of device.
Paul Farrell is an Associate Director of Audiology Professional Practices at the American Speech-Language-Hearing Association