FOI 1013-2025/26- Sound detector technology

Request:

I am interested in the growing use of technology capable of detecting "sound events" which is being deployed, often in conjunction with CCTV systems, to monitor public areas.

This technology is designed to use audio inputs to detect sounds such as gun shots, human screams or shouts, speeding vehicles or anti-social behaviour to improve public safety.

Here are some examples of the type of technology I'm referring to:

https://soundeventdetector.eu/sound-event-detection-for-security/

https://north.tech/news/north-to-make-westminster-smarter-and-safer-through-1-2-million-contract-award/

I am trying to establish the extent to which this technology is currently being used in the UK by police forces where the force operates its own CCTV network in public areas such as town centres or road networks.

Specifically, I would like to ask:

Q1. Is your force using, or has it previously tested, sound detector technology as described above to monitor public areas for emergencies or anti-social behaviour?

Q2.  If yes, please provide details of how many sound detectors or sound detector-equipped CCTV cameras you are operating and when they were installed.

To be clear, this request does not apply to CCTV or monitoring systems which can broadcast sound via a loudspeaker, for example to issue a public warning. It applies only to technology which monitors public spaces for audio or noise events.

Secondly, this request does not apply to CCTV or monitoring equipment operated by local authorities. It applies only to systems directly operated by police forces.

Response: 

Decision

Your request for information has now been considered and North Yorkshire police can neither confirm nor deny (NCND) that information is held as the duty in S1(1)(a) of the Freedom of Information Act 2000 (the Act) does not apply by virtue of the following exemptions:

Section 24(2) National Security

Section 31(3) Law Enforcement

Section 31 and 24 are prejudice based qualified exemptions and any prejudice (harm) that confirming or denying information is held would cause must be articulated as well as the public interest considerations.

Evidence of Harm:

Any disclosure under FOI is a release to the public at large. Whilst not questioning the motives of the applicant, confirming or denying if a particular policing tool of this type is used (including where it has been trialled) would risk revealing sensitive information about the surveillance capability of the force. Any disclosure under FOIA is a disclosure to the world at large, and confirming or denying the use of specialist techniques would prejudice law enforcement.

If the requested information were held by the force, confirmation of this fact would reveal that North Yorkshire Police has access to specific surveillance technology which have the capability to be used in covert operations. Irrespective of whether they are used in such a way or not, confirming use or trial of such tools identifies a capability of the force in an area of policing which is covert. The result would undermine operations as criminals, including terrorists, would gain a greater understanding of the police's surveillance methods and techniques, enabling them to take steps to counter them.

Conversely, if information were not held by the force, and a denial were issued, this would reveal to those same individuals, the potential limitations of police surveillance capabilities in this area. This may further encourage offending by confirming to those involved in criminality including terrorism where such surveillance measures are not available to police. Any identification of a reduced technical capability in the field of surveillance would substantially prejudice the ability of forces to police their areas which would lead to a greater risk to the public. 

This detrimental effect is increased if the request is made to several different police forces. In addition to the local criminal fraternity now being better informed, those intent on organised crime throughout the UK will be able to ‘map’ where the use of certain surveillance tactics are or are not deployed. This can be very useful information to those committing crime including terrorism, and could lead to them moving their operations, destroying evidence, or avoiding those areas; all of which undermine the tactic and risk the integrity and success of covert operations and future prosecutions.

Any information that identifies the focus of policing capability and activity, particularly covert activity, and could be used to the advantage of terrorists or criminal organisations to commit crime, undermines the operational integrity of these activities. This will adversely affect public safety, impact national security, and prejudice law enforcement.

Public Interest Test:

Factors favouring confirming or denying whether any other information is held for Section 24

The public is entitled to know where its public funds are being spent.

A better-informed public can take steps to protect themselves.

Factors against confirming or denying whether any other information is held for Section 24

Confirming or denying the use of specialist techniques could render security measures less effective by compromising ongoing or future covert operations undertaken to protect the security or infra-structure of the UK. This increases the risk of harm to the public.

Factors favouring confirming or denying whether any other information is held for Section 31

Disclosure reinforces the wider commitment to openness and transparency to facilitate public debate. Greater transparency inherently leads to improved public confidence, which in turn may increase the public’s engagement with the police.

Factors against confirming or denying whether any other information is held for Section 31

To confirm or deny information is held would compromise the police’s ability to protect the public. Disclosing North Yorkshire Police surveillance capabilities would provide people committing crime or those with the criminal intent with information that would increase the effectiveness of their criminality and assist them in evading detection. The resultant effect of this prejudice would undermine current and future operational strategies within covert investigations and when gathering evidence. The integrity of investigations and the tactics used as part of them is of paramount importance when it comes to protecting the public from all types of crime, but in this case, particularly in serious and organised crime and terrorism. Any compromise of these tactics which results in prejudice to the effectiveness of an investigations, will place the public at significant risk. To do so is clearly not in the public interest.

Balance test

Whilst there is a public interest in transparency as a route to accountability when it comes to the use of surveillance tactics in investigations, forces are already held to account by statute, for example the Police and Criminal Evidence Act and the Regulation of Investigatory Powers Act, as well as by independent bodies such as His Majesty’s Inspectorate of Constabulary and Fire & Rescue Services (HMICFRS), The Independent Office for Police Conduct (IOPC) and the Office of the Surveillance Commissioner (OSC). Accountability is therefore not enhanced by confirming or denying whether any information is held in respect of a specific tactic. 

The security of the country and safety of its people is of paramount importance, and the public entrust the police service to make appropriate decisions regarding their safety and protection. To do so, the police must be cautious with any information that is released. It must be considered that a release of information under FOI is a disclosure to the world at large, including to those who have cause to use it for criminal means. Confirming or denying whether information is or isn’t held would reveal to the world, specific details about the force’s surveillance capability, and that would assist those individuals and groups intent on causing harm in the ways evidenced above. Any incident that results from confirmation or denial would, as a result, affect National Security and undermine operational law enforcement.

Therefore currently, it is our opinion the balancing test for confirming or denying whether any information is held regarding these techniques is not made out.

None of the above can be viewed as an inference that the information you seek does or does not exist.

Please note that systems used for recording information are not generic, nor are the procedures used locally in capturing the data.  It should be noted therefore that this force’s response to your questions should not be used for comparison purposes with any other responses you may receive.