UK lockdown alert guide & audio library
Lockdown Alarm Sounds & Voice Alerts
A lockdown alarm should communicate a different response from a normal fire evacuation. This guide explains what a lockdown alarm should sound like, when a tone or voice message may be appropriate, what current UK education guidance says, and lets you listen to 32 alarm tone samples available for Camelott systems.
The aim is not to find the loudest or most dramatic sound. It is to choose an alert that is distinctive, understood, appropriate to the site and supported by a rehearsed procedure.
Guide reviewed 27 August 2026 • Current DfE and Martyn's Law position checked against GOV.UK
The key principle
A lockdown alert must mean something different
In a fire, the normal response is usually to evacuate. During a lockdown or other security incident, leaving a room or moving towards a normal exit may increase risk. That is why the alert and the procedure behind it need to be clearly distinguishable.
Department for Education guidance says that where an existing alarm system such as a fire alarm is used to provide a threat alert, the threat signal must differ in some way from the actual fire-alarm sound.
The guidance does not prescribe one universal UK lockdown tone. It asks settings to consider whether their chosen method is quick to activate, reaches everyone who needs to know and does not increase the risk to the person raising the alert.
Choosing an alert
What should a lockdown alarm sound like?
A suitable alert is not selected by tone name alone. It needs to work in the building, remain distinguishable from routine signals and be understood by staff, learners, visitors and anyone else included in the site's emergency plan.
Clearly different from the fire alarm
Avoid a signal that could cause occupants to instinctively evacuate. This is particularly important where the existing fire system, school bell or public-address equipment is also used for other routine signals.
Easy to recognise after training
A tone does not need to sound frightening. It needs to be distinctive enough that trained staff immediately recognise it and know which procedure to follow.
Audible where people actually are
Assess classrooms, offices, halls, kitchens, toilets, workshops, detached buildings, playgrounds and other occupied areas. Ambient noise and building construction affect real-world audibility.
Supported by visual alerts where needed
Flashing beacons can supplement sound in noisy areas and where hearing needs or the environment mean an audible alert alone may not reliably reach everyone.
Simple enough to understand under pressure
If several tones or codes are used, each needs a defined purpose and staff must be able to recall the meaning. Complexity can undermine an otherwise capable alarm system.
Linked to a controlled all-clear
The initial warning, reset and any all-clear message should be part of one documented procedure. Staff should know who is authorised to end the response.
Tone, voice or both?
Lockdown tone vs voice annunciation
Both approaches can be useful. The better choice depends on the site's procedures, acoustics, user needs and how much information the first alert needs to communicate.
Option 01
Distinctive alarm tone
A dedicated tone is immediate and uncomplicated, but people must already know what it means. It is strongest where staff training and drills consistently link one sound to one response.
- Fast: a short activation can warn the whole designed coverage area.
- Simple: no spoken message needs to be heard or interpreted.
- Training dependent: occupants need to know the meaning in advance.
Option 02
Voice annunciation
A voice annunciator can add context or a clear instruction to the initial alert. Wording should remain concise, intelligible and aligned with the site's written emergency procedure.
- More explicit: a spoken instruction can carry more meaning than a tone alone.
- Flexible: different messages can support different planned responses where the equipment and procedure allow.
- Needs good intelligibility: acoustics, background noise and message length matter.
Option 03
Tone followed by voice
Some sites prefer an attention-grabbing distinctive tone followed by a short voice message. This can combine immediate recognition with additional instruction, subject to the site's risk assessment and procedures.
Listen before you choose
32 lockdown alarm sounds
These audio files are the tone samples currently published by Camelott. Use them as a comparison library rather than assuming that a particular numbered tone is automatically suitable for every site.
Audio players use preload="none" so the page does not unnecessarily fetch all
32 MP3 files when it first loads. Voice-annunciation wording and configuration
are dealt with separately as part of system design.
Avoid dangerous ambiguity
Why a lockdown alarm should not sound like the normal fire alarm
The two alerts can require opposite behaviour. A familiar fire signal can trigger immediate movement towards exits, while a security threat may require occupants to remain in a room, secure doors or avoid a particular route.
- Fire signal is recognised Occupants commonly associate the normal fire alarm with leaving the building by the established evacuation route.
- Security response may be different A lockdown, invacuation or threat-specific evacuation may require a different direction of travel or no movement at all.
- The threat signal therefore needs its own meaning A distinct sound, voice message, code or combination can separate the security response from routine fire evacuation.
- Training completes the communication The signal only works operationally when people understand what it means and what they are expected to do.
Current legal position
Lockdown alarm sounds and Martyn's Law
A particular alarm sound does not make a premises “Martyn's Law compliant”. The legislation is concerned with proportionate preparedness, procedures and—where applicable—additional protective measures.
As of 27 August 2026, the substantive requirements of the Terrorism (Protection of Premises) Act 2025 are not yet in force. The Security Industry Authority says the Act is expected to come into force in spring 2027.
For standard-tier premises, the legislation focuses on appropriate public-protection procedures covering evacuation, invacuation, lockdown and communication. Government guidance also makes clear that organisations do not have to buy a particular specialist product or service simply to comply.
Applying the guidance
How Camelott configures lockdown alerts
The sound is selected as part of the wider surveyed system rather than treated as a stand-alone feature. The aim is to make activation, coverage and the chosen warning method work together.
- Distinct alert options: choose an appropriate alarm tone that can be kept separate from the site's normal fire signal.
- Voice annunciation: suitable systems can incorporate voice messages where additional instruction is required.
- Visual warning: flashing beacons can supplement audible alerts.
- Survey-led coverage: sound levels and occupied areas are considered during the site survey and commissioning process.
- Indoor, detached and outdoor areas: the design can consider classrooms, offices, halls, portacabins, playgrounds and suitable external spaces.
- Multiple activation methods: fixed call points and authorised portable triggers can be positioned around the site.
- Supplementary notifications: monitoring, desktop, email and SMS options can be included where required.
- Handover and training: nominated staff can be shown activation, reset, testing and the configured alert functions.
Authoritative guidance
Sources schools and organisations should read
Equipment should support the organisation's emergency plan. These official sources explain the wider responsibilities and should be read alongside any supplier information.
- Department for Education — Protective security and preparedness for education settings Education-specific guidance covering incident alerts, communication, lockdown, invacuation, evacuation, testing and preparedness.
- Home Office — Terrorism (Protection of Premises) Act 2025 statutory guidance Current statutory guidance explaining scope and the duties that will apply when the substantive requirements commence.
- Security Industry Authority — Understanding Martyn's Law Current regulator guidance on scope, tiers, commencement and preparation.
- Camelott — Lockdown Alarm for Schools: practical UK guide Broader explanation of school lockdown alarms, procedures, system components, planning, testing and evaluation.
Common questions
Lockdown alarm sounds FAQs
The answers below separate sound-selection principles from wider legal and emergency-planning responsibilities.
What should a lockdown alarm sound like?
There is no single universal UK lockdown tone prescribed for every school or workplace. The important point is that the alert is distinctive, understood by the people who must act and appropriate to the site's emergency procedures. In education settings, Department for Education guidance says that if an existing alarm system is used for a threat alert, the signal must differ from the normal fire-alarm sound.
Should a lockdown alarm sound different from a fire alarm?
Yes. A fire alarm normally prompts evacuation, while a lockdown may require people to remain inside, secure rooms or restrict movement. Using the same signal for both responses risks creating dangerous ambiguity.
Is a tone or a voice message better for a lockdown alarm?
Either can form part of a suitable system. A distinctive tone is simple and fast but relies on staff knowing exactly what it means. Voice annunciation can add clear instructions or identify a response, but the message still needs to be intelligible, rehearsed and appropriate to the site's plan. Some sites use both.
Can a school use its existing fire alarm for lockdown?
Department for Education guidance lists use of existing alarm infrastructure as one possible option, but says the threat signal must differ from the actual fire-alarm sound. The school should also consider whether the chosen method can be activated quickly and reach everyone who needs to receive the warning.
Does Martyn's Law require a specific lockdown alarm sound?
No. The Terrorism (Protection of Premises) Act 2025 is focused on proportionate public-protection procedures and, for enhanced-tier premises, additional measures. It does not prescribe one particular lockdown tone or require a specific branded alarm product.
Is Martyn's Law already in force?
Not yet. As of 27 August 2026, the substantive duties are expected to come into force in spring 2027. Organisations that may be in scope can prepare now, but there is not yet a legal duty to comply with the substantive requirements.
Do schools fall into the enhanced tier at 800 people?
Early years, primary, secondary and further-education premises have a special provision: if they are in scope at 200 or more people, they remain in the standard tier even if 800 or more people may be present. Higher-education premises do not have that special treatment.
Can a lockdown alarm include an all-clear signal?
Yes, where the site's emergency procedure calls for one. The all-clear should be controlled by authorised staff and should not be confused with the initial alert. The exact reset and all-clear process should be documented and trained.
Should lockdown alarms use voice alerts as well as sirens?
Voice annunciation can be useful where a site wants an alert to carry more information than a tone alone. Whether it is appropriate depends on the site's procedures, acoustics, accessibility needs and the wording staff are trained to follow.
How do you know whether a lockdown alarm can be heard everywhere?
Coverage should be assessed in the real environment. Classrooms, halls, kitchens, toilets, offices, detached buildings, playgrounds and noisy areas can all behave differently. Camelott's installation process includes site assessment and commissioning rather than relying only on a nominal sounder rating.
Continue your research
Choose the page that matches your next step
Keep the search intent separated: use the school guide for education and planning, the systems page for product capabilities, and the installation page for surveys and quotations.