The Mosquito works by exploiting a medical condition called presbycusis — or more simply put age-related hearing loss. As we age, our ability to hear higher frequency sounds is reduced. The Mosquito works by emitting an alternating high-frequency tone at 16-18.5 kilohertz. The tone is highly annoying and is used to prevent and disperse teenagers congregating outside property and business premises. It switches on and off four times a second for up to 20 minutes which isn’t audible to people over about 25 years of age but is intensely irritating to people under that age. For the youth setting the frequency comes out of the speaker in a 60-degree arc and can reach 15-30 metres depending on the volume setting.
