ISO 7240-19:2007

Fire detection and alarm systems - Part 19: Design, installation, commissioning and service of sound systems for emergency purposes

ISO 7240-19:2007 specifies the design, installation, commissioning and service requirements for a sound system for emergency purposes (s.s.e.p.), which is primarily intended to broadcast information for the protection of lives within one or more specified indoor or outdoor areas during an emergency. The s.s.e.p. is intended to initiate a rapid and orderly mobilization of occupants in an emergency by including systems using loudspeakers to broadcast voice announcements for emergency purposes, alert signals complying with ISO 7731 (where applicable) and evacuation signals complying with ISO 8201. In some cases, sound systems are used in preference to sounders or bells in order to broadcast a range of coded warnings that is difficult to communicate with sounders or bells. The use of the s.s.e.p. for normal sound reinforcement and distribution systems purposes under non-hazardous circumstances is not excluded. When used for non-emergency purposes, the zoning of the loudspeakers can differ from the zones used for emergency purposes. ISO 7240-19:2007 does not apply to sound systems that use bells or sounders.

Systèmes de détection et d'alarme d'incendie — Partie 19: Conception, installation, prise en charge et entretien des systèmes sonores pour les besoins de secours

General Information

• Status: Published
• Publication Date: 12-Aug-2007
• ICS: 13.220.20 - Fire protection
• Technical Committee: ISO/TC 21/SC 3 - Fire detection and alarm systems
• Drafting Committee: ISO/TC 21/SC 3 - Fire detection and alarm systems
• Current Stage: 9093 - International Standard confirmed
• Start Date: 10-Mar-2025
• Completion Date: 13-Dec-2025

Overview

ISO 7240-19:2007 - "Fire detection and alarm systems - Part 19" - defines requirements for the design, installation, commissioning and service of sound systems for emergency purposes (s.s.e.p.). The standard covers systems intended to broadcast voice announcements, alert signals (ISO 7731) and evacuation signals (ISO 8201) to protect lives in one or more indoor or outdoor areas during an emergency. It applies to loudspeaker-based emergency voice alarm systems and excludes systems that rely solely on bells or sounders.

Key topics and technical requirements

• System purpose and scope: Broadcast emergency voice messages, alert and evacuation tones to initiate safe, orderly occupant response.
• Design & planning: Responsibilities, qualifications, documentation and zoned loudspeaker layout for emergency and non-emergency use.
• Speech intelligibility: Measurement and performance requirements (see Annex A) to ensure messages are clear and actionable.
• Warning signals: Requirements for compliance with ISO 7731 and ISO 8201 for alert and evacuation tones.
• Power & reliability: Power supply requirements, backup calculations and circuit supervision to ensure operation under fault conditions (see Annex C).
• Wiring & supervision: Supervision of transmission paths, compatible wiring materials and interconnection with fire detection/alarm systems.
• Control & indication: Sound system control and indicating equipment functions, access levels and optional features.
• Commissioning & testing: Detailed commissioning procedures, test and inspection reports (Annex D–F) and certification requirements.
• Operation & service: Routine tests, maintenance plans, documentation and qualifications for service personnel.
• Human factors: Use of visual and tactile warning devices where required and classification of priorities for messages.

Practical applications & users

ISO 7240-19 is intended for:

• Fire safety engineers and system designers specifying emergency voice alarm systems.
• AV and security system integrators installing and commissioning s.s.e.p. solutions.
• Facility managers and building owners implementing occupant warning and evacuation systems.
• Authorities having jurisdiction and certification bodies assessing compliance and approvals.
• Maintenance teams producing service plans, routine tests and documentation.

Typical applications include large public buildings, transport hubs, stadia, shopping centres, industrial sites and campuses where intelligible voice messaging and zoned evacuation are required.

Related standards

• ISO 7240 series (Parts 1, 2, 4, 13, 16)
• ISO 7731 (auditory danger signals)
• ISO 8201 (audible evacuation signal)
• IEC 60331-23, IEC 61672-1, EN 54-24
• IEC 60849 (basis for this ISO part)

Using ISO 7240-19:2007 helps ensure emergency voice alarm systems meet recognized international performance, safety and serviceability expectations.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 7240-19
First edition
2007-08-15
Fire detection and alarm systems —
Part 19:
Design, installation, commissioning and
service of sound systems for emergency
purposes
Systèmes de détection et d'alarme d'incendie —
Partie 19: Conception, installation, prise en charge et entretien des
systèmes sonores pour les besoins de secours

Reference number
©
ISO 2007
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©  ISO 2007
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ii © ISO 2007 – All rights reserved

Contents Page
Foreword. v
Introduction . vii
1 Scope . 1
2 Normative references . 1
3 Terms, abbreviated terms and definitions . 2
3.1 Definitions . 2
3.2 Abbreviated terms . 3
4 Design requirements . 4
5 Planning. 4
5.1 Responsibilities . 4
5.2 Qualifications . 4
5.3 Documentation. 4
5.4 System design. 5
5.5 Category of s.s.c.i.e. 6
5.6 Classification of priorities. 7
5.7 Speech intelligibility . 7
5.8 Warning signals . 8
5.9 Emergency loudspeaker zones. 9
5.10 Visual warning devices and tactile warning devices . 10
5.11 Delay to outputs. 10
5.12 Initiation . 11
5.13 Manual alarm output. 11
5.14 Sound system control and indicating equipment . 11
5.15 Power supply. 12
5.16 Supervision of transmission paths. 13
5.17 Wiring. 13
5.18 Interconnection to a fire detection and alarm system . 14
5.19 Use for non-emergency purposes . 14
5.20 Documentation. 15
6 Equipment and material . 16
6.1 Quality of components. 16
6.2 Standards . 16
6.3 Additional requirements . 16
6.4 Sound system control and indicating equipment optional functions. 16
6.5 Installation materials . 16
7 Systems compatibility. 16
7.1 Responsibility . 16
7.2 Documentation. 17
7.3 Certification . 17
8 Approvals . 17
9 Installation . 17
9.1 Responsibility . 17
9.2 Qualifications . 17
9.3 Certification . 18
10 Commissioning . 18
10.1 Responsibility . 18
10.2 Qualifications . 18
10.3 Procedure. 18
10.4 Certification . 18
11 Normal use. 18
11.1 Access to system. 18
11.2 Other responsibilities . 18
11.3 Routine tests and regular controls . 19
11.4 Documentation . 19
11.5 Operating instructions. 19
12 Service. 19
12.1 Responsibility. 19
12.2 Qualifications. 19
12.3 Service plan . 19
12.4 Documentation . 21
13 Abnormal situations — System disconnection . 22
Annex A (normative) Measurement of speech intelligibility. 23
Annex B (informative) Explanation of access levels. 26
Annex C (informative) Power source calculations. 28
Annex D (informative) Commissioning report . 30
Annex E (informative) Inspection report . 31
Annex F (informative) Test report . 32
Bibliography . 33

iv © ISO 2007 – All rights reserved

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 7240-19 was prepared by Technical Committee ISO/TC 21, Equipment for fire protection and fire fighting,
Subcommittee SC 3, Fire detection and alarm systems.
This first edition of ISO 7240-19 together with ISO 7240-16 cancels and replaces IEC 60849:1998, which has
been technically revised.
ISO 7240 consists of the following parts, under the general title Fire detection and alarm systems:
⎯ Part 1: General and definitions
⎯ Part 2: Control and indicating equipment
⎯ Part 4: Power supply equipment
⎯ Part 5: Point-type heat detectors
⎯ Part 6: Carbon monoxide fire detectors using electro-chemical cells
⎯ Part 7: Point-type smoke detectors using scattered light, transmitted light or ionization
⎯ Part 8: Carbon monoxide fire detectors using an electro-chemical cell in combination with a heat sensor
⎯ Part 9: Test fires for fire detectors (Technical Specification)
⎯ Part 10: Point-type flame detectors
⎯ Part 11: Manual call points
⎯ Part 12: Line type smoke detectors using a transmitted optical beam
⎯ Part 13: Compatibility assessment of system components
⎯ Part 14: Guidelines for drafting codes of practice for design, installation and use of fire detection and fire
alarm systems in and around buildings (Technical Report)
⎯ Part 15: Point type fire detectors using scattered light, transmitted light or ionization sensors in
combination with a heat sensor
⎯ Part 16: Sound system control and indicating equipment
⎯ Part 19: Design, installation, commissioning and service of sound systems for emergency purposes
⎯ Part 21: Routing equipment
⎯ Part 22: Smoke-detection equipment for ducts
⎯ Part 27: Point-type fire detectors using a scattered-light, transmitted-light or ionization smoke sensor, an
electrochemical-cell carbon-monoxide sensor and a heat sensor
⎯ Part 28: Fire protection control equipment
A part 26 dealing with oil mist detectors is under development.
vi © ISO 2007 – All rights reserved

Introduction
A sound system for emergency purposes (s.s.e.p.) alerts occupants to a hazard that can require their safe and
orderly evacuation from the building. It operates automatically or manually. Equipment to alert building
occupants is, therefore, required to function after the hazard has been detected. Fire in a building is a
common hazard that is often detected by an automatic fire detection and alarm system. A s.s.e.p. can operate
as part of a fire detection and alarm system or can function in conjunction with other emergency detection
systems.
When used for emergency purposes, it is recommended that the s.s.e.p. form part of a complete facility
(equipment, operating procedures and training programmes) for the control of emergencies.
The s.s.e.p. can be the subject of approval by relevant authorities.
This part of ISO 7240 has been prepared by ISO/TC 21/SC 3 and is based on IEC 60849:1998, Sound
systems for emergency purposes prepared by the International Electrotechnical Commission IEC/TC 100
Audio, video and multimedia systems and equipment.
This part of ISO 7240 contains specific requirements for the design, installation, commissioning and service of
sound systems for emergency purposes and follows the general format specified in ISO/TR 7240-14.

INTERNATIONAL STANDARD ISO 7240-19:2007(E)

Fire detection and alarm systems —
Part 19:
Design, installation, commissioning and service of sound
systems for emergency purposes
1 Scope
This part of ISO 7240 specifies the design, installation, commissioning and service requirements for a sound
system for emergency purposes (s.s.e.p.; see ISO 7240-1:2005, Figure 1, item C), which is primarily intended
to broadcast information for the protection of lives within one or more specified indoor or outdoor areas during
an emergency. The s.s.e.p. is intended to initiate a rapid and orderly mobilization of occupants in an
emergency by including systems using loudspeakers to broadcast voice announcements for emergency
purposes, alert signals complying with ISO 7731 (where applicable) and evacuation signals complying with
ISO 8201. In some cases, sound systems are used in preference to sounders or bells in order to broadcast a
range of coded warnings that is difficult to communicate with sounders or bells.
The use of the s.s.e.p. for normal sound reinforcement and distribution systems purposes under
non-hazardous circumstances is not excluded. When used for non-emergency purposes, the zoning of the
loudspeakers can differ from the zones used for emergency purposes.
This part of ISO 7240 does not apply to sound systems that use bells or sounders.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 7240-1:2005, Fire detection and alarm systems — Part 1: General and definitions
ISO 7240-2, Fire detection and alarm systems — Part 2: Control and indicating equipment
ISO 7240-4, Fire detection and alarm systems — Part 4: Power supply equipment
ISO 7240-13, Fire detection and alarm systems — Part 13: Compatibility assessment of system components
ISO 7240-16:—, Fire detection and alarm systems — Part 16: Sound system control and indicating equipment
ISO 7731, Ergonomics — Danger signals for public and work areas — Auditory danger signals
ISO 8201, Acoustics — Audible emergency evacuation signal
IEC 60331-23, Tests for electric cables under fire conditions — Circuit integrity — Part 23: Procedures and
requirements — Electric data cables
IEC 61672-1, Electroacoustics — Sound level meters — Part 1: Specifications
EN 54-24, Fire detection and fire alarm systems — Part 24: Components of voice alarm systems —
Loudspeakers
3 Terms, abbreviated terms and definitions
3.1 Definitions
For the purpose of this document, the terms and definitions, together with Figure 2, given in ISO 7240-1:2005
and the following apply.
3.1.1
acoustically distinguishable area
a.d.a.
subdivision of an emergency loudspeaker zone, that may be an enclosed or otherwise physically defined
space, characterized by an individual reverberation time and an ambient noise level
3.1.2
area of coverage
area, inside and/or outside a building or structure, where the s.s.e.p. meets the requirements of this part of
ISO 7240
NOTE Certain parts of an area can be excluded, see 5.4.4.
3.1.3
automatic mode
mode of operation of a s.s.e.p. that is linked to a fire-detection system or other means of triggering the sound
system to broadcast emergency messages without human intervention, in a manner that is pre-set according
to an agreed evacuation policy
3.1.4
cabinet
housing that affords a degree of protection and robustness to its constituent parts and subassemblies
3.1.5
competent person
person who, in relation to the work undertaken, has the necessary knowledge, skill and experience to
complete the work satisfactorily and without danger or injury to any person
3.1.6
control point
location from where the evacuation is controlled
NOTE The control should be undertaken by competent persons.
3.1.7
emergency microphone
microphone dedicated for use by competent personnel during the voice alarm condition
3.1.8
emergency loudspeaker zone
subdivision of the premises composed of one or more acoustically distinguishable areas, such that the
occurrence of an emergency within it is indicated separately from any other subdivision
NOTE When used for non-emergency purposes, the zoning of the loudspeakers may differ from the zones used for
emergency purposes.
3.1.9
listener
person of normal hearing and who is able to understand the language used
2 © ISO 2007 – All rights reserved

3.1.10
manual mode
mode of operation where an operator is directly in control of the broadcast of live or pre-recorded sounds,
especially those of an emergency nature
3.1.11
quiescent condition
functional condition characterized by the absence of the voice alarm, fault warning, disabled and test
conditions
3.1.12
reference ambient noise level
sound pressure level spectrum with a reference to 20 µPa, together with the A-weighted sound pressure level,
expressed in dBA per octave band, from 125 Hz to 8 kHz (centre frequencies) of the ambient noise level that
is unlikely to be exceeded for more than 10 % of the time in emergency mode
NOTE 1 The reference ambient noise level is expressed in decibels.
NOTE 2 The reference ambient noise level is used in the assessment of speech intelligibility.
NOTE 3 Where the reference ambient noise level exceeds 90 dBA, satisfactory speech intelligibility becomes
increasingly difficult to achieve.
3.1.13
sound system control and indicating equipment
s.s.c.i.e
equipment complying with ISO 7240-16 that is used to
a) receive alarm signals from an emergency detection system(s),
b) receive audio messages from emergency microphones,
c) determine signal priority and routing,
d) cause audible warning signals to be broadcast to emergency loudspeaker zones,
e) automatically supervise the correct functioning of the system and give audible and visible warning of
specified faults,
f) provide manual controls and visual status indicators
3.1.14
transmission path
physical connection between sound system components (external to the cabinet of the component) used for
the transmission of information, including audio and/or power
3.1.15
voice alarm condition
alert signal, evacuate signal, recorded or live emergency signal broadcast in at least one emergency
loudspeaker zone
3.2 Abbreviated terms
⎯ a.d.a. acoustically distinguishable area
⎯ s.s.c.i.e. sound system control and indicating equipment
⎯ s.s.e.p. sound system for emergency purposes
4 Design requirements
A s.s.e.p. shall be designed, installed, commissioned and serviced in accordance with requirements of this
part of ISO 7240. The design shall also consider any national regulations that place other limitations on the
design, such as
a) the maximum size of emergency loudspeaker zones,
b) interface requirements to an emergency detection system,
c) installations in explosive atmospheres.
5 Planning
5.1 Responsibilities
Planning of the s.s.e.p., including components and usage requirements, shall be undertaken in a systematic
process in accordance with a quality system, such as ISO 9001.
5.2 Qualifications
The planning of the s.s.e.p. shall be undertaken by persons having qualifications and/or experience relevant to
the scope of the particular design requirements.
NOTE National regulations can exist for the registration and recognition of individuals with the requisite qualifications
and experience. The recognition can form part of a recognized competency framework.
5.3 Documentation
5.3.1 Emergency management plan
A documented emergency management plan for the building or structure shall be prepared. The emergency
management plan shall consider the following:
a) occupancy use of the building or structure;
b) number of people likely to occupy the building or structure and changes in occupancy levels;
c) time required to evacuate the building or structure;
d) need for people to control the evacuation of emergency loudspeaker zones;
e) need for the use of an alert signal in conjunction with the evacuate signal;
f) use of phased evacuation (For buildings and structures over 25 m effective height, the alert signal
duration and any automatic sequencing of the warning signal should consider horizontal and vertical
exiting, occupant characteristics, the building design approach, affected compartments and adjacent
compartments as a sequence and management in use principles.);
g) need for and specification of speech messages (The need and specification should consider agreed
scripts and voice characteristics, such as language, dialect and gender, of persons trained in the proper
use of microphones, for making the pre-recorded messages.);
h) s.s.c.i.e. category (see 5.5);
i) location of equipment, such as emergency microphones, main and remote equipment;
4 © ISO 2007 – All rights reserved

j) evacuation zone information (When used for non-emergency purposes, the zoning of the loudspeakers
may differ from the zones used for emergency purposes. The planning documentation should specify any
zoning differences to assist in the system design.);
k) the physical limits of each emergency loudspeaker zone;
l) access to the s.s.e.p. (The party requesting the s.s.e.p. should provide an emergency management plan
as part of the initial specification. Where the emergency management plan is not available, the designer
should develop the emergency management plan in consultation and agreement with the owner and the
relevant authorities. The emergency management plan may need to be approved by the relevant
authority.).
5.3.2 Documentation necessary to prepare design
5.3.2.1 The designer shall have access to documentation necessary to design the s.s.e.p. in accordance
with the requirements of this part of ISO 7240. Documentation shall include the following:
⎯ plans of the building;
⎯ acoustic report, including
⎯ a schedule of the a.d.a.(s) for each emergency loudspeaker zone (The total area of the a.d.a.(s)
within each emergency loudspeaker zone should be equal to the total area of the emergency
loudspeaker zone.),
⎯ predicted or measured reverberation time of each a.d.a. in at least the 500 Hz, 1 000 Hz and
2 000 Hz octave bands,
⎯ reference ambient noise level in each a.d.a.;
⎯ description of the hazard;
⎯ description of the environmental conditions such as
⎯ temperature,
⎯ humidity,
⎯ corrosive atmosphere,
⎯ electromagnetic influences (e.g. areas subject to severe thunderstorms);
⎯ description of the environment where the equipment is installed (e.g. occupancy of the building,
hazardous locations);
⎯ emergency management plan.
5.3.2.2 The designer shall state any assumptions made and provide justifications for solutions selected.
5.4 System design
5.4.1 The s.s.e.p. shall permit the broadcasting of intelligible information on measures to be taken for the
protection of lives within one or more emergency loudspeaker zones. The audible warning signals shall be
distributed throughout the appropriate emergency loudspeaker zones by a system of loudspeakers.
Consideration should be given to the need for the distribution of warning signals for the hearing-impaired via
means other than loudspeakers, such as
a) visual warning devices, such as strobes and high-intensity LEDs;
b) induction-loop systems, where they augment a sound re-enforcement system;
c) other sensory systems.
The designer should consider the features of different s.s.c.i.e. categories (see 5.5) and ensure that an
appropriate category is selected for the application.
5.4.2 The s.s.e.p. shall be operated in accordance with an emergency management plan, including the live
broadcasting of messages.
5.4.3 The following criteria shall be fulfilled.
a) When any alarm occurs, the s.s.e.p. shall immediately disable or override any functions not connected
with alarm condition (such as paging, music or general pre-recorded announcements being broadcast to
the loudspeaker zones requiring emergency broadcasts).
Where a phased evacuation is implemented, non-emergency broadcasts may continue to emergency
loudspeaker zones within the building not currently affected by the emergency. This may be used to
promote the orderly evacuation of building occupants and should be considered as part of the overall
emergency management plan.
b) Unless damaged as a result of the emergency, or repair or service, the s.s.e.p. shall be available for
operation at all times. In the event of unavailability due to service, suitable provisions shall be made for
alternative methods of communication under all prevailing circumstances until the s.s.e.p. is restored to
full functionality.
c) The s.s.e.p. shall be able to broadcast warning signals and speech messages to one or more areas
simultaneously. There shall be at least one warning signal alternating with one or more speech messages
for this purpose.
d) All messages shall be clear, short, unambiguous and, as far as practicable, pre-planned.
e) The content of all messages and the language(s) used shall be specified and/or approved by the
purchaser and relevant authorities.
5.4.4 The design may exclude from the area of coverage defined areas rarely or never occupied by people.
5.5 Category of s.s.c.i.e.
5.5.1 Each s.s.c.i.e. shall be categorized based on the inclusion of additional functions (see ISO 7240-16:—,
Annex A) specified in Table 1.
The categories are based on evacuation strategy, risk and level of staff competency. The categories reflect
the degree of manual control required and should be appropriate to the risk and to the availability of trained
personnel to operate the s.s.e.p. A category 4 system is not necessarily more effective than a category 1
system and can be less effective for building occupants if manual controls are used inappropriately.
5.5.2 Additional optional functions permitted in ISO 7240-16 (e.g. alert signals complying with ISO 7731)
may be included with each category.
NOTE The addition of optional functions provides design flexibility so that the appropriate solutions can be specified
for particular applications.
6 © ISO 2007 – All rights reserved

Table 1 — Category of s.s.c.i.e.
Category Optional Functions
a b c d
1 2 3 4
— 9 9 9 Emergency microphone
— — 9 9 Emergency loudspeaker zone group microphone control
— — — 9 Manual mode control
a
No optional functions are required for an s.s.c.i.e. to be categorized as category 1. Category 1 offers automatic operation of the
s.s.e.p. in accordance with a preprogrammed set of evacuation rules. The category 1 s.s.e.p. is under the sole control of the emergency
detection system.
b
In addition to the automatic functions provided by category 1, a category 2 s.s.e.p. provides functions to broadcast live messages
by means of at least one all-call microphone located at a control point.
c
In addition to the functions of category 2, a category 3 s.s.e.p. provides functions to broadcast live messages to preselected
emergency loudspeaker zones or groups of zones. Category 3 allows for evacuation control where an automatic evacuation plan might
not be appropriate in all circumstances.
d
In addition to the functions of category 3, a category 4 s.s.e.p. provides functions to select and direct stored emergency messages
to preselected emergency loudspeaker zones or groups of zones. Category 4 s.s.e.p. also includes functions to enable and disable
broadcast messages and display their status. Category 4 allows competent staff to implement evacuation control with a higher degree of
selectability than category 3.
5.6 Classification of priorities
5.6.1 In automatic mode only, the order of priority for the message distribution shall be based upon
a) any automatic programmed response,
b) the perceived risk to occupants, which may require manual alarm output control of the programmed
response.
5.6.2 Events shall be prioritized according to their urgency.
The following primary levels are recommended but there can be advantages in adding further subgroups,
depending on the operational strategies of the emergency management plan for the building or structure:
a) evacuate: potentially life-threatening situation needing immediate evacuation;
b) alert: dangerous situation nearby requiring warning of impending evacuation;
c) non-emergency: operational messages, e.g. s.s.e.p. tests, etc.
The use of these levels in descending order of priority ensures that appropriate alarm signals and messages
are provided first to the emergency loudspeaker zones at immediate risk.
5.7 Speech intelligibility
5.7.1 General
Unless otherwise specified in mandatory national standards, the requirements of either 5.7.2 or 5.7.3 shall
apply.
5.7.2 Measurement method
The speech intelligibility in 90 % of the a.d.a., and in any other areas exceeding 10 m within the a.d.a., shall
be measured in accordance with one of the methods described in Annex A and shall be not less than the
values given in Table 2.
Table 2 — Required speech intelligibility values
Required values
Measurement method
Mean intelligibility value measured
Minimum intelligibility value measured
chosen
a
across all applicable areas in the a.d.a.
across all applicable areas in the a.d.a.
STI or STIPA 0,50 0,45
r
PB 256 words, % 94 91
PB 1000 words, % 77 68
MRT, % 94 90
SII 0,50 0,45
a 2
Where Annex A requires only one measurement point (for an a.d.a. less than 25 m ), a single measurement may be taken for both
the mean and minimum intelligibility value.
The speech intelligibility requirements are considered to be a reasonable minimum, although in some very
reverberant spaces and areas with very high ambient noise levels this can be impractical to achieve. In such
cases, an acceptable level of intelligibility should be agreed by the relevant authorities and all other interested
parties.
5.7.3 Prescriptive method
Within the a.d.a., the s.s.e.p. shall satisfy the following requirements.
a) The average reverberation time across 500 Hz, 1 kHz and 2 kHz octave bands is not greater than 1,3 s.
b) The reference ambient noise level is less than 65 dBA.
c) The sound pressure level of voice messages is greater than 75 dBA L , measured over a period of not
eq
less than 10 s.
d) The distance between the centres of the loudspeakers is not greater than
⎯ 6 m for unidirectional loudspeakers,
⎯ 12 m for bidirectional loudspeakers.
e) The unobstructed distance between a loudspeaker and any listener is not greater than
⎯ 6 m for unidirectional loudspeakers,
⎯ 7,5 m for bidirectional loudspeakers.
When calculating the distance to the loudspeaker, seated listeners shall be taken as being 1,2 m above
the floor and standing listeners shall be taken as being 1,6 m above the floor.
5.8 Warning signals
5.8.1 Alert and evacuate signals
5.8.1.1 For buildings and structures where the emergency management plan requires the use of both the
alert signal (e.g. where assisted or directed evacuation of occupants is required) and the evacuate signal, the
alert signal shall precede the evacuate signal within the relevant emergency loudspeaker zone.
8 © ISO 2007 – All rights reserved

5.8.1.2 When the alert signal is used, it shall continue to operate until manual alarm output control of the
s.s.e.p. is taken, or if not responded to in a prescribed time from initiation, it shall be automatically replaced by
an evacuate signal. The prescribed time shall be in accordance with the emergency management plan and
shall not exceed 10 min.
The primary use of the alert signal is to signal to competent evacuation staff that they should attend
designated points to receive further instructions regarding the emergency or evacuation of the emergency
loudspeaker zone. In other buildings and structures with occupants trained in the operation of the
management plan, the alert signal may be used to signal to occupants to prepare for further instruction. The
instruction may be the initiation of the evacuate signal to commence the evacuation.
5.8.2 Evacuate signal only
5.8.2.1 For buildings and structures where the emergency management plan requires the unassisted or
immediate evacuation of occupants, the s.s.e.p. may be configured to immediately generate the evacuate
signal, without the use of an alert signal.
Evacuation signals, other than the signal specified in ISO 8201, may be mandated by national requirements.
5.8.2.2 The evacuate signal shall include a verbal message stating “Emergency” and “Evacuate now”.
These messages shall be inserted in the time period between the temporal pattern phases in accordance with
ISO 8201.
ISO 8201 permits the insertion of longer additional voice messages between evacuate signal cycles. More
detailed messages, giving specific instructions, should be included as part of the emergency-management
plan.
5.9 Emergency loudspeaker zones
5.9.1 General
5.9.1.1 The s.s.e.p. shall be divided into emergency loudspeaker zones if required by the emergency
management plan. It is not necessary that the emergency loudspeaker zones be the same as other zones, for
example emergency detection zones or non-emergency loudspeaker zones.
5.9.1.2 In determining emergency loudspeaker zones, the following criteria shall apply.
a) The intelligibility of messages broadcast in one zone shall not be reduced below the requirement of 5.7 by
the broadcasting of messages in other zones or from more than one source.
b) A single emergency detection zone shall not contain more than one emergency loudspeaker zone.
For non-emergency use, an emergency loudspeaker zone can be subdivided into smaller zones.
5.9.2 Loudspeakers
Unless otherwise specified in national regulations, loudspeakers shall comply with the requirements of
EN 54-24.
5.9.3 Output of loudspeakers
5.9.3.1 At all places within the emergency loudspeaker zone where warning signals are conveyed to
building occupants, the A-weighted sound pressure level during the “On” phases of the audible warning
signals, measured with the time-weighting characteristic F (Fast) (see IEC 61672-1), shall exceed by a
minimum of 10 dB the ambient sound pressure level averaged over a period of 60 s and shall not be less than
65 dBA nor more than 105 dBA at the listener position.
Measurement should be taken in the normal standing positions on the floor of coverage.
5.9.3.2 If the audible warning signals are intended to arouse sleeping occupants, the minimum
A-weighted sound pressure level of the signal shall be 75 dBA at the bedhead, with all doors closed.
75 dBA might not be adequate to awaken all sleeping occupants and other tactile and visual signals can be
required.
5.9.3.3 Loudspeakers installed within the vicinity of the s.s.c.i.e. shall not inhibit or adversely affect the
operation of the s.s.c.i.e. In particular, care shall be taken that the proximity and power setting for any
speakers near the s.s.c.i.e. do not cause acoustic feedback when the microphone is used.
Where it is important that occupants, such as patients in hospital wards, not be subject to the possible stress
imposed by loud noises, the sound pressure level and content should be arranged to provide warning for the
staff and minimize trauma.
5.9.4 Loudspeaker installation
5.9.4.1 Loudspeakers shall be permanently mounted.
5.9.4.2 Each incoming and outgoing conductor of the same potential shall be connected to a separate
screw or clamping facility on a terminal block. Terminal blocks shall be securely fixed to the loudspeaker.
Tools or special equipment shall be required to disconnect conductors from the terminal block.
NOTE Tools include screw drivers and special equipment includes ladders but not chairs.
5.9.4.3 Conductors shall be supported and connected so that there is no undue mechanical stress on the
conductors or the terminations to which they are connected.
5.10 Visual warning devices and tactile warning devices
5.10.1 In areas having high ambient noise levels, the s.s.e.p. shall be reinforced by a system of visual
warning devices or other devices to provide sensory stimulation adequate to the needs of the person at risk.
The temporal pattern described in ISO 8201 shall be imposed on the visual and tactile evacuation signals.
5.10.2 Visual warning devices shall be installed in areas where the background A-weighted ambient noise
level exceeds 95 dBA or where the wearing of hearing protection devices is required or where required by
national requirements for hearing-impaired persons.
5.11 Delay to outputs
5.11.1 Where required by the emergency management plan, the s.s.e.p. shall introduce a delay before
entering the voice alarm condition. In this case the following shall apply.
a) There shall be provision to switch on and switch off delays by means of a manual operation at access
level 2; see Annex B.
b) There shall be provision to automatically switch on and/or switch off delays by means of a programmable
timer, which shall be configurable at access level 3.
5.11.2 The delay may be introduced for the following events:
⎯ before the alert signal (e.g. to allow a person to investigate an alarm);
⎯ between the alert signal and the evacuate signal (e.g. to allow competent personnel to attain designated
points to receive additional information);
⎯ before the evacuate signal (e.g. to allow a person to investigate an alarm).
10 © ISO 2007 – All rights reserved

5.12 Initiation
The s.s.e.p. shall be initiated by either an emergency detection system, manual call point or at the s.s.c.i.e.
The use of a timer may delay the broadcast of the warning signal in accordance with an emergency
management plan.
5.13 Manual alarm output
A manual alarm output control shall be installed for a category 4 s.s.c.i.e at a main control point and also at
remote control points specified by any relevant authority to allow
a) switching on or off of selected loudspeaker zones,
b) selection of appropriate of pre-recorded messages,
c) starting or stopping of pre-recorded messages,
d) broadcasting of live messages (if any) via the microphone.
NOTE On large projects, there are often two distinct types of emergency microphone:
⎯ full function – normally only one microphone located in a control room and used by competent staff;
⎯ restricted function – several microphones in locked cabinets in public places (for example
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