Police dismiss concerns about new anti-riot acoustic device

November 18, 2019 13:21
Sunday was the first time the LRAD (circled in red) was used in anti-riot operations in Hong Kong. The police insist the acoustic device is a 'broadcasting system' and not a weapon. Photo: HKEJ

Police have dismissed fears over a new acoustic device they deployed on an anti-riot vehicle over the weekend, insisting that it does not pose a risk to people's health. 

Reacting to allegations that the acoustic device may be emitting an ultra-low frequency that could lead to dizziness, nausea or loss of sense of direction, the police said such talk is unwarranted. 

The device was merely a broadcasting tool that helps anti-riot personnel deliver important messages to people on the street during a noisy environment, the police said in a press release, stressing that the system cannot be described as a weapon.

The statement came amid intense discussions among netizens after a Long-Range Acoustic Device (LRAD) was seen deployed during an operation to disperse protesters at the Hong Kong Polytechnic University (PolyU) on Sunday.

It was the first time that the LRAD, which was purchased back in 2009, had been used in the ongoing anti-protester operations that began in June, raising worries that the police were deploying a new sound-related "weapon" to quell the street demonstrations.  

Commonly known as a “sound cannon”, the LRAD is an acoustic hailing device mainly developed to convey important messages over a long range in a noisy environment, according to the police.

On Sunday afternoon, a Unimog armored vehicle of the police, with an LRAD installed on it, was apparently used to warn violent demonstrators who had gathered near PolyU. 

Reporting on the new tool, media outlets helped bring up questions about the anti-riot device and its potential side-effects on people's sense of hearing. 

Responding to the news reports and online chatter, the police said in a government press release in the evening that “the LRAD is a broadcasting system but not a weapon.”

“Unlike what is said in individual media reports, the LRAD does not generate ultra-low frequency which will cause dizziness, nausea or loss of sense of direction,” the press release said.

According to the statement, the LRAD was meant to “convey important messages over a long range in a noisy environment”, and that there are “strict guidelines and regulations” regarding the use of the acoustic device.

In 2012, John Lee Ka-chiu, then acting secretary for security, said the LRAD can "effectively help the police convey important messages over a long range in a noisy environment, in a bid to preserve public safety, public order and prevent injury to life and property."

Answering a lawmaker’s questions about the device in the Legislative Council, Lee said “the LRADs will not be used in public meetings and processions.”

According to Lee, they “can only be used together with the armored vehicles in circumstances such as serious disasters, counter-terrorism operations or severe security incidents for broadcasting purposes in a noisy environment with an aim to effectively convey messages to the crowd over a long range or to facilitate evacuation exercises, etc.”

Lee, however, admitted that since “the LRAD can produce significantly loud sound, any improper use of the device (ie continuous broadcasting with maximum volume range from an unsafe distance and angle) may cause hearing impairment."

"In this connection, there are stringent rules and operational guidelines on the use of this kind of devices,” the official said.

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