The mayor of Rotterdam will invest in about 15 more Mosquito alarms to avoid young people loitering.
On July 27, Mayor Ahmed Aboutaleb said the city of Rotterdam would buy 15 Mosquito alarms of a new generation as tests performed with the new devices went well.
Mosquito alarms are sound devices that emit high frequency sounds only heard by young people, usually under 25 including infants.
They are used to avoid loitering or gathering of people as the strident music, approximately above 17 kHz, quickly becomes too much irritating. The machines are nicknamed mosquitoes because of the buzzing sound they makes.
Invented in 2005, it is widely used in the United Kingdom or Australia. Philadelphia or Chicago in the United States also adopted the device.
Without disturbing the older people unable to hear the sound, it is controversial because it can be considered as a discriminatory sonic weapon. Moreover, the safety of these high frequency sounds remains uncertain, specifically for babies. The sound was once also developed as a mobile ringtone.
The mayor of Rotterdam said he received many requests to install the machines and refused some of them. The sound system would only be turned on around parks between 10:00 pm and 06:00 am, but not during the days.
According to Nos, the device has been used by about 100 municipalities in the Netherlands in the last 15 years.