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LCQ4: Long Range Acoustic Device

     Following is a reply by the Acting Secretary for Security, Mr John Lee, to a question by the Hon Cyd Ho Sau-lan in the Legislative Council today (November 28):


     It was reported in the press on October 19 this year that the Police had procured a new type of weapon called Long Range Acoustic Device (commonly known as "sound cannons"), which could be used to disperse participants of demonstrations and public gatherings. The press reports also pointed out that the sound cannons could produce high frequency sound waves which could impair the hearing of persons within a short distance from the device. In response to the press report, the Police issued a press release on the same day stating that the Police had put in place very strict codes and guidelines on the use of the device, and that the device would only be used in anti-riot operations. In this connection, will the Government inform this Council:

(a) of the details of the sound cannons, including the model, efficacy, lethality, coverage, and potential hazards to human health (including immediate and permanent damages), and whether they will harm people who are not the target;

(b) of the weaponry used by the Police, prior to the procurement of the sound cannons, for handling the situations which are now handled by the sound cannons; whether the Police's procurement of the sound cannons was due to the inadequacies of such weaponry; if there were inadequacies of such weaponry, of the details; whether the Police had other reasons for procuring the sound cannons; whether they have plans to procure more sound cannons; and

(c) how the Police determine what situations are "riots" which call for the use of sound cannons; of the channels through which the public may inspect the Police's codes and guidelines on the use of sound cannons; whether the authorities have consulted healthcare professionals and the Independent Police Complaints Council on the codes; if they have, of the views collected; if not, the reasons for that?



     To maintain their operational and response capability, the Police Force regularly review and renew their equipment with reference to such equipment used by their counterparts around the world. The Administrationˇ¦s reply to the Member's question is as follows:

     First, I must point out that the Long Range Acoustic Device (LRAD) procured by the Police Force is a broadcasting system, not a weapon. It can effectively help the Police to 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.

     In line with the circumstances and operational needs, various police districts and formations currently use sound devices of different types and models, including portable and floor-type broadcasting devices as well as public announcement (PA) systems on police vehicles (such as patrol vehicles and motorcycles). According to the Police's actual operational experiences, the effective transmission range of the PA systems on police vehicles is estimated to be around 50 metres. As the sound quality, volume and transmission range of such systems are comparatively inferior to those of the LRADs, they are not in a position to competently achieve the effect of making long range public announcements in a noisy environment.

     In procuring armoured vehicles in 2009, the Police Tactical Unit Headquarters also purchased two LRADs with an effective transmission range of about 300 metres. The two devices can only be used together with the armoured 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.

     In addition, subsequent to the incident of Hong Kong residents being taken hostage in the Philippines in 2010, the Police Negotiation Cadre (PNC) reviewed measures of handling critical incidents of similar nature. At the time the incident took place, the distance between the local police officers who were handling the incident and the coach on which the hostages were being kept was over 100 metres, rendering it difficult for the officers to communicate with the abductor. In the light of this incident, the PNC considered it necessary to procure a sound device for effective communication over a long range. Two portable LRADs were then purchased for handling critical incidents. For instance, in hostage-taking incidents whereby the Police are confronted, for the security of on-spot officers, negotiators may use such a device to initiate a conversation with the abductor(s) at a safe distance. In cases of attempted suicide whereby the person attempting to commit suicide is at a dangerous location, such as the Tsing Ma Bridge, negotiators may start a conversation by means of this device for the purpose of life-saving. The effective transmission range of the two portable LRADs is about 250 metres.

     The four LRADs go with an "alert tone" function. According to the manufacturer's information, the "alert tone" is similar to the siren used by the Police and the Fire Services Department. Its frequency is within our normal hearing range and it can easily draw public attention. It is also indicated in the manufacturer's information that, unlike what is said in some of the reports, the LRADs do not generate ultra-low frequency which will cause dizziness, nausea or loss of sense of direction to the recipients. The Police stress that the purpose of procuring the LRADs is to convey important messages over a long range in a noisy environment.

     So far, the Police have not used the LRADs in any one of their operations, while reiterating that the LRADs will not be used in public meetings and processions.

     According to the safety guidelines provided by the manufacturer, as 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 operational guidelines were compiled with strict adherence to the manufacturer's safety guidelines. Officers operating the LRADs must receive prior operational and safety trainings, and they should strictly adhere to the operational guidelines. Any use of LRADs shall be approved by the highest officer-in-charge of the formation concerned (ie an officer of Superintendent to Chief Superintendent rank), and its on-site use shall be approved by an officer of Inspectorate rank or above. The LRAD must be operated by designated officers who have received prior trainings. In case the highest volume range shall be used, another trained officer must be present to assist in observing the actual surroundings to ensure that the operator achieves the objective of the operation in a safe manner without causing impairment to any persons around.

Ends/Wednesday, November 28, 2012
Issued at HKT 15:45


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