Mosquito Machine

The Five Senses and Beyond: The Encyclopedia of Perception - Jennifer L. Hellier 2017

Mosquito Machine

The Mosquito machine (or Mosquito alarm) was designed to discourage teenagers from loitering. The Mosquito machine works by emitting a high-frequency sound that can only be heard by people under 25 years of age. Younger people find the high-frequency sound annoying and will not loiter in areas with the sound. The Mosquito machine also discourages vandalism and graffiti by deterring youth from spending time in an area with the sound. Older people, on the other hand, are unable to hear the sound and are unaffected by the Mosquito machine.


Howard Stapleton (1966—) developed the Mosquito machine in 2005 in Wales. He released the technology to be purchased as an alarm through his company, Compound Security Solutions, in 2006. Later, Moving Sound Technologies started distributing the Mosquito machine in North America. Initially, Stapleton aimed his product at shop owners in cities with teen loitering problems. The Mosquito machine currently has customers throughout the world including school districts, shops, and transit hubs.

The Mosquito machine works by emitting high-pitched sound only audible to people under 25 years of age. The sound was selected because adults cannot hear the pitch; the sound is annoying to those who can hear it, yet exposure to the sound is not believed to damage hearing. Moving Sound Technologies, the company that markets the Mosquito machine in North America, has audio demonstrations on their website that allow people to test their hearing and determine whether they can hear the Mosquito machine pitches (Mosquito Audio Demo, 2012). Moving Sound Technologies also claims that the Mosquito machine is safe for all ages, meets all known U.S. sound regulations, and will not bother younger children or dogs (Mosquito FAQs, 2012).

Current Use

Currently, the companies marketing the Mosquito machine report successful use in many countries, but not all cities are welcoming the use of this technology. Opposition to the Mosquito machine is based on the idea that specifically targeting teenagers is discriminatory and may violate basic human and civil rights. The sound can be viewed as an invasion of personal space, and concerns have been raised that exposure to high-frequency sound could be damaging to hearing. Any action to target a specific group of people could later have discriminatory uses, particularly when the technology could be used to prevent people in a certain age range from moving around freely in public.

To address these concerns, cities may impose limits on the time and duration of use of the Mosquito machine. The city of Sheffield in South Yorkshire, England, has completely banned use of Mosquito machines. Other cities may consider limiting the duration and time of use of the Mosquito machine. For example, schools have reported a decrease in vandalism if the Mosquito machine is on during the hours when students should not be at the school. If the Mosquito machine continues to be used, in the future, cities may be challenged by human rights activists or concerned parents to limit or ban the use of Mosquito machines.

Not to be dissuaded by concerns about age discrimination, teenagers have found ways to make the Mosquito machine technology useful rather than antagonistic by creating a cellphone ringtone using the same frequencies. The ringtone, often called teen buzz, can be heard by teens and people under age 25, but not by most adults. Since many schools require ringers and alerts on cellphones to be silenced during classes, the teen buzz ringtone allows teens to communicate during class using a ringtone that most of their teachers cannot hear.


Additional studies need to be conducted to verify the safety of high-pitched sounds on children’s hearing. If the Mosquito machine continues to be viewed as a valid option to prevent teen loitering and the resulting vandalism, cities may be challenged to create laws surrounding the approved use of this technology.

Lisa A. Rabe

See also: Age-Related Hearing Loss; Auditory System; Tinnitus

Further Reading

Compound Security Systems. (2014). Mosquito MK4 (anti-loitering device). Retrieved from

Local teen wins campaign to ban controversial device. (2011, February 22). Sheffield Telegraph. Retrieved from

Mosquito Audio Demo. (2012). Retrieved from

Mosquito FAQs. (2012). Retrieved from