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Running Head: TIME TO EVACUATE

Time to Evacuate: Fire Alarms Systems Are Failing to

Address Their Intended Purpose

Christopher O’Neil

University of Cincinnati

Milestone 4: Term Paper

June 9, 2012

Author Note

This is an extensive study of the course material prepared for Analytical Approaches for the Fire

and Emergency Services, Section 707, taught by Professor John Glass.

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Abstract

Fire alarm systems’ limitations in prompting adequate evacuation were analytically argued. This

paper presented quantified information to support the Temporal-Three sound’s lack of

recognisability and perceived urgency, the lack of adequate messages to building occupants, and

the lack of direction provided by fire alarm systems’ audible devices. All three areas are

discussed in relation to occupant behaviour (i.e. roles) during evacuations. Arguments were

further integrated with a review of relevant legislation, standards, and regulations. The use of

course material such as review of statistical studies, presenting quantified data, using statistical

measures, and cost-benefit analysis were used to support arguments. This paper concluded with

recommendations to increase the control over building evacuation. These were: educating the

public on the T-3 sound, its characteristics, and where/when it may be encountered; creating

standards and regulations to guide users in constructing effective messages that are used in mass

notification and emergency communication systems; using building codes to enforce mass

notification and emergency communication systems; and using building codes to enforce

directional sound technology in applications that require a cost effective approach to optimize

evacuation times.

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Table of Contents

Abstract ……………………………………………… 3

Introduction ……………………………………………… 4

Analysis ……………………………………………… 5

Argument 1 ……………………………………………… 5

Argument 2 ……………………………………………… 6

Argument 3 ……………………………………………… 8

Discussion ……………………………………………… 10

Conclusion & Recommendations ……………………………………………… 11

References ……………………………………………… 13

Appendices ……………………………………………… 15

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Time to Evacuate: Fire Alarms Systems Are Failing to Address Their Intended Purpose

Fire alarm systems provide early detection of environmental changes associated with fire

(smoke, heat, etc.) to stimulate two actions in people. These are emergency response and

building evacuation. Emergency response has been increasingly better and easier to achieve over

the years because governments have reinforced inspections and ensured code compliance

through legislation, which directly improves early detection. However, fire alarm systems fail to

control building evacuation. The same bodies of legislation that reinforces early detection and

emergency response inadequately supports evacuation by failing to acknowledge a fire alarm

system’s limitations in the area. It is not a technology problem, but rather fiscal support and the

lethargic process of policy and governance (Boynowski, 2010). Academia in the fire and

evacuation fields acknowledges this loophole and advocate for a change. Within these fields, it is

believed that occupants respond to fire in an adaptable way from a variety of influences beyond

what fire alarm systems currently address. The current legislation assumes occupants evacuate

immediately after the sound of a fire alarm; falsely assuming complete control over evacuation.

There is a disconnection between the built environment governed by legislation and the

philosophical and psychological understanding of human behaviour supported by academia.

In support for academia, legislation needs to address the short comings of a fire alarm

system. Presented are three analytical arguments that reinforce this notion with respects to

building evacuation. Fire alarm systems fail to produce a sound that is widely recognisable and

perceived with urgency, fail to deliver adequate messages to building occupants, and fail to

provide direction that influences an evacuee’s choice of egress. It is hoped that fire

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administrators become educated on the assumptions made by fire alarm systems and advocate for

a change in their community.

Analysis

Argument One

The temporal-three (T-3) patterns is a sound that is widely used in North American fire

alarm systems to promote building evacuation (Proulx & Laroche, 2003). It is regulated by ISO

8201 and adopted by NFPA 72, and the National Building Code of Canada (Proulx & Laroche,

2003). Despites T-3 integration into legislation, it fails to be recognized by the general public.

An unrecognized sound could promote building occupants to desire more information rather than

evacuating, which is common role adopted by humans after a fire alarm sounds (Bryan, 2003, p.

4-1). Proulx and Laroche (2003) conducted an experiment that tested the T-3 recognisability

alongside other commonly encountered sounds. These sounds were a car horn, a reverse alarm,

fire alarm bell, the slow whoop, fire alarm bell, and an industrial warning buzzer (National

Research Council Canada, 2010). The two other fire alarms, slow whoop and fire alarm bell,

were common to the United States and extensively used in Canadian industrial buildings at the

time of the study, respectively (Proulx & Laroche, 2003). After considering Bennett and Briggs

(2003) guidelines to analyzing statistical studies, it was concluded that findings presented by

Proulx and Laroche (2003) are reliable to reproduce (p. 311-316). That is, the source is unbiased,

the variables of interest were well defined and measured sufficiently, results were presented

fairly, and the study is reproducible (Bennett & Biggs, 2003, p. 311-316). Table A displays

Proulx and Laroche (2003) findings in terms of recollection, identification, and perceived

urgency. For example, the T-3 was recalled by 71% of the participants, correctly identified as a

fire alarm sound by 6% of the participants, and had a mean urgency of 3.97 on a scale of one to

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ten with ten being of highest urgency. Recollection was any prior experience with the sound,

identification was attributing the sound to a name or description, and perceived urgency was the

level of a required response to the sound (Proulx & Laroche, 2003).

Table A – Recollection, Identification, and Perceived Urgency of T-3

SOUND RECOLLECTION (%)

YES / NO

IDENTIFICATION (%)

CORRECT / INCORRECT

PERCEIVED URGENCY

MEAN / STD. DEV.

T-3 71 29 6 94 3.97 2.42

Industrial Buzzer 81 19 2 98 4.91 2.74

Car Horn 97 3 98 2 4.93 2.46

Reverse Alarm 91 9 71 29 5.60 2.78

Slow Whoop 52 48 23 77 6.01 2.50

Fire Alarm Bell 58 42 50 50 7.17 2.74

Table A suggests that the T-3 is not correctly identified by most people. Participants commonly

related the T-3 to domestic sounds such as a busy phone signal, phone beep, or PA pre-

announcement (Proulx & Laroche, 2003). Proulx (2007) later noted that fire alarm sounds can be

misinterpreted as a burglar alarm, elevator fault, or security door alarm in non-domestic

environments. From Table A, it can be further suggested that most people fail to perceive the T-3

as urgent. It has the lowest level of perceived urgency in comparison to the other sounds. Proulx

and Laroche (2003) noted that the Fire Alarm Bell and Slow Whoop were identified within a

high urgency range whereas the T-3 was within a low urgency range. The other sounds were

within a medium urgency range (Proulx & Laroche, 2003). Fire alarm systems fail to promote

evacuation, especially when their T-3 sound is not widely recognizable and not perceived as

urgent.

Argument Two

Beyond being recognizable and perceived as urgent, fire alarm systems fail to deliver

sufficient messages to inform building occupants during emergencies. New trends have joined

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fire alarm systems with mass notification or emergency communication systems to access a more

flexible level of communication. Both have been standardized by NFPA 72 and regulated by

UFC 4-021-01, but fail to be recognized by the National Building Code of Canada (Boynowski,

2010). They provide real-time information to all building occupants by utilizing a variety of

interfaces (i.e. SMS text, email, voice communication) during emergency situations to ensure

delivery of messages promoting faster evacuation (Boynowski, 2010; Mircom Group, 2012).

Their application stemmed from the realization of a misconceived notion; fire alarms are

sufficient to prompt evacuation. In actuality, humans do not respond to fire alarms like ball

bearings by immediately evacuating via the closest egress point upon the sound of an alarm

(Galea, 2009). They require more information to effectively evaluate their level of risk and

assume adoptive roles based on their current knowledge of the situation. The less information

provided equates to less desirable roles like searching for fire. This was evident during the MGM

Grand Hotel Fire where a series of communication errors led up to a devastating outcome (see

Appendix A for a complete list of data). Bryan (2003) discovered that males were more likely to

initially notify others (16.3%), searched for fire (14.9%), or handle an extinguisher (6.9%);

instead of leaving the building (4.2%; p. 4-22). Females were more likely to initially notify

others (13.8%), call the fire department (11.4%), and locate family (11%); instead of leaving the

building (10.4%; Bryan, 2003, p. 4-22). Despite the NFPA 72 and UFC 4-021-01 existence, they

do not entirely address all the problems associated with communication (Kuligowski, 2011, p. 2).

These systems can increase negligence in building occupants when messages are too long

(Kuligowski, 2011, p. 7). Kuligowski, in a preliminary NIST report, provided benchmarks to

construct effective messages. These were supported by other research studies. Chandler

concluded that messages should contain 27 words, 3 sentences, 9 seconds long, and be front

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loaded with most important and relevant information (as cited in Kuligowski, 2011, p. 7).

Furthermore, Doug and Fung noted that a live voice that does not deliver daily non-emergency

messages is most effective (as cited in Kuligowski, 2011, p. 7). Chandler also concluded that text

messages are most effective when written at a 6th

grade level, or four grades below the United

States average reading level (as cited in Kuligowski, 2011, p. 8). Standardizing requirements that

stipulate the construction and content of messages to occupants during emergencies will improve

the effectiveness of these systems. Also, the recognition by legislation will ensure their use in the

built environment.

Argument Three

In addition to effective messages, building occupants would be prompted to evacuate

quicker if a fire alarm system provided audible direction. Directional sound utilizes people’s

ability to localize sound sources, even around corners, which helps navigate occupants to exits

(O’Connor, 2005). This provides flexibility over line-of-sight methods (i.e. fire exit signs) since

building users unconsciously learn to neglect their presence over time. An experiment conducted

by the University of Ulster randomly sampled 500 people after leaving a store that had 14

emergency exit signs (O’Connor, 2005). It was concluded that 75.2 % of participants did not

notice or identify correctly any emergency exit signs (O’Connor, 2005). Directional sound

supplements a traditional fire alarm system’s alarm sound. Traditional alarm sounds (i.e. T-3) are

prescribed by codes to achieve specific sound levels in all building areas, whereas directional

sound provides sound cues assisting occupants in locating nearby exits (O’Connor, 2005).

Directional sound achieves exit localization by using different frequencies of sounds ranging

from fast and slow; faster sounds indicate closer exits (see Appendix B for an illustration).

Directional sound is not recognized by legislation, creating a missed opportunity for fire alarm

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systems to promote faster and more effective building evacuation (O’Connor, 2005). University

of Leeds Professor Withington has conducted several pilot trials that exemplify faster evacuation

times in a variety of settings when comparing the use of visual signs and the combination of

directional sound and visual signs. Table B reports these findings from three of Withington’s

(2002) pilot trails, which involved smoke and non-smoke filled environments (p. 5-7).

Table B – Evacuation Times in Pilot Trials testing Directional Sound

PILOT TRAIL VISUAL SIGNS (s) COMBINATION (s) 1

DIFF. (s) DIFF. (%)

Complex Maze (smoke) 124 51.3 72.7 58.6 Complex Maze (no smoke) 14 7 7 50 Open Space (smoke) 14.5 7.3 7.2 49.7 Open Space (no smoke) 5.5 4.9 0.6 10.9 Left/Right (smoke) 67.8 7 60.8 89.7 Left/Right (no smoke) 8.8 6 2.8 31.8 1 jointly uses directional sound and visual signs

The data above suggests that the combination of directional sound and visual signs hastens

evacuation in different circumstances. Pilot trials Complex Maze led participants through a series

of rooms to a safe exit, Open Space required participants to locate an exit after being positioned

in the centre of a large open spaced room, and Left/Right required participants to locate the

available exit positioned directly to their left or right (Withington, 2002, p. 5-7). Smoke filled

pilot trials resulted in the greatest differences in evacuation times. Further evidence to support

the effectiveness of directional sound can be illustrated in a cost-benefit analysis (CBA). Table C

provides a CBA outlining the additional costs and benefits awarded to a fire alarm system that

integrates directional sound with its current system.

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Table C – Cost Benefit Analysis for Directional Sound

COST BENEFITS (EGRESS TIME)

Install (%) Per Unit ($) Average Improvement (s) Average Improvement (%)

Directional Sound 4 - 8% more 130.93 25.2 40.95

The average cost would only be an additional 4 – 8 % of the current fire alarm system

(O’Connor, 2005). Individual units range in cost depending on features, supplier, and quantity.

For example, Amazon sells a System Sensor PF24V ExitPoint Direct Sounder with Voice

Messaging for $191.79 (Amazon, 2012). Total Computing Life Safety sells the same model

starting at $130.93 and declining as higher quantities are purchased (Total Computing Life

Safety, 2012). The benefits are associated with egress times. They reflect the mean differences in

seconds and percentage derived from the different trials in Table B, which indicate evacuation

improvements. Directional sound is a cost effective approach to improve on the short comings of

fire alarm systems by providing direction for occupants during evacuation.

Discussion

Three arguments supporting the notion that fire alarm systems inadequately evacuate

building occupants were provided all of which address academia’s position on human behaviour

during fire. Roles that are adopted by occupants are influenced by a variety of environmental

interpretations including the fire alarm system. Acknowledging the fact that fire alarm systems

are responsible for building occupant behaviour and their adopted roles generates a space to

create changes that account for their short comings. For example, since fire alarm sounds (i.e. T-

3) were recognized as ambiguous, the implementation of voice communication systems helped

clarify emergency incidents by providing messages. The same philosophy can be used to change

the framework of today’s fire alarm systems. By standardizing the structure and content of

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messages used in mass notification and emergency communication systems accepts the fact the

more can be done to increase the control over building evacuation. As mentioned earlier,

technology does not seem to be the problem. The current financial burdens and slow paced

policy has staged the built environment, as directed by building and fire codes, far behind

technological advancements and research findings. Both, directional sound and mass notification

systems fail to be enforced by the National Building Code of Canada. The T-3 has been enforced

since 1996 by the National Building Code of Canada, but Proulx & Laroche’s (2003) research

indicated low recognisability and perceived urgency even years after its enactment making

participants in the fields of fire and evacuation question the disconnect between public education

and public policy. There is a gap between what we know is safe for building occupants and how

we legislate it.

Conclusion and Recommendations

In conclusion, fire alarm systems fail to adequately evacuate building occupants. A

common role assumed by occupants after interpreting a fire alarm sound is to look for more cues.

This can be influenced in the lack of recognition of the T-3 sound, commonly used in North

American fire alarm systems, by mistakenly identifying it with domestic sounds, burglar alarms,

elevator faults, or security door alarms. This misidentification could attribute to its low sense of

urgency by the general public. It is recommended that programs should be developed to educate

the general public on the T-3 sound, its characteristics, and when it may be encountered (see

Appendix C for a listed format of recommendations). Furthermore, the ambiguous sounds of a

fire alarm system (i.e. T-3) can lead occupants to adopting unfavorable roles like searching for

fire. Mass notification and emergency communication systems are aimed at engaging building

occupants by delivering real-time information through a variety of interfaces to promote

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favorable roles like evacuating the endangered area. However, since they have been newly

standardized and regulated there is a lack of guidance in constructing effective messages. Too

long of a message may produce negative effects like negligence. It is recommended that

standards and regulations guide users in constructing effective messages. In addition to a lack of

guidance, mass notification and emergency communication systems have not been recognized by

the National Building Code of Canada. It is recommended that building codes of all levels

enforce their use in applications where communication requires real-time information exchange

with all occupants. Lastly, current legislation fails to enforce directional sound which can be a

cost effective approach to reducing evacuation times. Directional sound helps occupants to

localize exits faster than line-of-sight devices in smoke and non-smoke filled environments. This

technology can improve evacuation times by 40.95% while only costing 4-8% of the current fire

alarm system. It is recommended that building codes enforce directional sound technology in

applications that require a cost effective approach to optimize evacuation times. Fire

administrators should continue to advocate for changes that can enhance control over building

evacuation.

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References

Amazon. (2012). System sensor pf24v exitpoint direct sounder with voice messaging. Retrieved

on June 9, 2012 from www.amazon.com/PF24V-ExitPoint-Directional-Sounder-

Messaging/dp/B001VS4MXG

Bennett, J. O., & Briggs, W. L. (2003). Essentials of Using and Understanding Mathematics: A

Quantitative Reasoning Approach. New York, NY: Addison Wesley.

Boynowski, D. (2010, August 8). Mass notification systems. Canadian Fire Alarm Association,

August 2010, 8-15.

Bryan, J. L. (2003). Human behaviour in fire. In Arthur E. Cote (Ed.), Fire protection

handbook (Vol 1). (20th

ed.). Quincy, MA: National Fire Protection Association.

Galea, E. (2009, May 6). 7 of 8: burning questions, model answers – the simulation of fire and

human behaviour [Video file]. Retrieved from www.youtube.com/watch?v=kV7bEm

9D4ko&feature=related

Kuligowski, E. D. (2011, February). Communicating the emergency: preliminary findings on the

elements of an effective public warning message. Washington, DC: National Institute of

Standards and Technology. Retrieved from www.nist.gov/customcf/get_pdf.cfm

?pub_id=907983

Mircom Group. (2012). Mircom mass notification system. Retrieved from www.mircomgroup

.com/products/product-lines/fx-mns.html

National Research Council Canada. (2010, August 26). Study shows low public recognition of

the temporal-three evacuation signal. Retrieved from http://www.nrc-

cnrc.gc.ca/eng/ibp/irc/ci/volume-6-n4-1.html

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O’Connor, D. J. (2005). Directional sound. NFPA Journal, 99, 50-56.

Proulx, G. (2007). Response to fire alarms. Retrieved from www.fpemag.com/archives/article

.asp ?issue_id=40&i=267

Proulx, G. & Laroche, C. (2003). Recollection, identification, and perceived urgency of the

temporal-three evacuation signal. Journal of Fire Protection Engineering, 13, 67-72.

Total Computing Life Safety. (2012). System sensor pf24v, exitpoint direct sounder with voice

messaging Retrieved on June 9, 2012 from http://www.totalcomputing.net/System-

Sensor-PF24V-ExitPoint-Directional-Sounder-wVoice-Messaging_p_1203.html

Withington, D. (2002). Life saving applications of directional sound. Retrieved from

www.systemsensor.com/exitpoint/pdf/life_saving_directional_sound.pdf

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Appendix A

First Actions by Occupants during the MGM Grand Hotel Fire

FIRST ACTION MALE (%) FEMALE (%)

Notified others 16.3 13.8

Searched for fire 14.9 6.3

Called fire department 6.1 11.4

Got dressed 5.8 10.1

Left building 4.2 10.4

Got family 3.4 11.0

Fought fire 5.8 3.8

Got extinguisher 6.9 2.8

Left area 4.6 4.1

Woke up 3.8 2.5

Nothing 2.7 2.8

Had others call fire department 3.4 1.3

Got personal property 1.5 2.5

Went to fire area 1.9 2.2

Removed fuel 1.1 2.2

Entered building 2.3 0.09

Tried to exit 1.5 1.6

Went to fire alarm 1.1 0.19

Telephoned others 0.8 1.6

Tried to extinguish 1.9 0.6

Closed door to fire area 0.8 1.3

Pulled fire alarm 1.1 0.6

Turned off appliances 0.8 0.9

Checked on pets 0.8 0.9

Other 6.5 2.5

Total (N = 25) 262 318

Note reproduced from Bryan, 2003, p. 4-22.

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Appendix B

Illustration of Directional Sound in a Building

Exit sign shaded quadrant represents visible face

Exit sign with designation of directional arrow

Directional sounder

Note reproduced from O’Connor, 2005.

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Appendix C

Recommendations

1. Programs should be developed to educate the general public on the T-3 sound, its

characteristics, and where/when it may be encountered

2. Standards and regulations should guide users in constructing effective messages for their

application in mass notification and emergency communication systems

3. Building codes should enforce the use of mass notification and emergency

communication systems in applications where communication requires real-time

information exchange with all occupants

4. Building codes should enforce directional sound technology in applications that require a

cost effective approach to optimize evacuation times