**1. Introduction**

In the event of a disaster, such as fire outbreak or earthquake, prompt evacuation to a safe zone is important and essential for ensuring the safety of evacuees. Facility managers are obliged to install fire extinguishing equipment, sufficient emergency exit and guide lights to make evacuee find proper path to the exit by the Japanese Fire Service Law, even if they are not familiar with the layout of the area [1]. Recently, several urban commercial premises have become huge and complex in order to provide efficiency and convenience. Evacuees are not able to intuitively find out evacuation routes in these buildings and structures without proper guidance to exits due to their spatial complexity. Active evacuation guidance systems have been developed to control different light and acoustic stimuli that provide evacuation guidance information to evacuees to construct a safe and secure evacuation environment [2–6].

Conventional evacuation guidance systems in buildings and structures are not designed to react to changes in situations, such as collapses or other disturbances.

Evacuation guidance systems must be able to autonomously determine which evacuation routes have not been damaged by the disaster to achieve rapid evacuation in emergency situations. An autonomous route-detection system, in which several smoke and heat sensors could be placed at key points in the objective area to determine the evacuation route based on the overall condition, was proposed [7]. An evacuation route guidance system that considers evacuees' current location and building safety using a smart building-sensor network and is able to recommend the best evacuation route for each localized evacuee through their mobile terminals was proposed and evaluated [8]. A method for determining evacuation routes has been proposed that uses location information from mobile devices to determine effective routes [9, 10].

It is crucial to guide the evacuees along the determined evacuation route to effectively use route-detection systems in disasters. However, the evacuation and pathway guide lights in the conventional evacuation guidance were not sufficient to lead the evacuees to the relevant routes adapted to the situation. Therefore, a system is required to guide evacuees flexibly in disasters. Several systems that help evacuees select the route to appropriately exit using light and sound stimuli have been proposed.

Several previous studies have researched active evacuation guidance systems that utilize the precedence effect (Haas effect) to help evacuee realize evacuation direction. It is a psychological feature in hearing acrostic stimuli. When two identical sounds are presented in close succession, the spatial location of the auditory stimulus is dominated by the first arriving sound [11]. Additionally, the implementation of sound equipment (such as loudspeakers and signal processors) and sound-stimuli presentations in evacuation guidance systems have been standardized by the Japan Lighting Manufactures Association (JLMA), such that evacuees can correctly identify evacuation routes [2]. Furthermore, an improved evacuation system utilizing the precedence effect, in which loudspeakers were set beside a wall in a passageway to avoid the disappearance of the precedence effect of an audio signal, was proposed [12, 13].

The evacuation guidance systems using the precedence effect able to lead evacuees to one or two exits predefined as an emergency exit, however, they provide only the direction to the exit and not a detailed evacuation path to the exit using acoustic stimulus. Therefore, the evacuee must discover an evacuation route to the exit using acoustic stimulus even if the guidance using the precedence effect to the exit were provided. If there were several obstacles in the current place, it might not be easy to avoid damaged passageways and a fire outbreak caused by a disaster.

Passengers and crew may quickly lose situational awareness in a smoke-filled cabin of an aircraft. The European Union Aviation Safety Agency (EASA) and Federal Aviation Administration (FAA) regulations stipulate requirements for emergency floor-path illumination in all aircraft to achieve faster evacuation. Thus, guiding pathways to exits makes sense in situations where vision does not work well. However, there are few studies that provide a pathway to exits using emitting acoustic stimuli sequentially. Therefore, in this study, we propose a new active evacuation guidance system using acoustic cues, in which guidance-sound stimuli are sequentially emitted along an evacuation path instead of relying on the precedence effect [6].

This study's objective is to develop an active evacuation guidance system to direct evacuees along an evacuation route by sequentially emitting sound stimuli. In the first stage of the study, we analyzed participants' capacity to identify sound stimuli

*Evacuation Guidance Assistance System Using Emitting Sound DOI: http://dx.doi.org/10.5772/intechopen.105223*

emitted through a set of loudspeakers. We conducted experiments to investigate the recognition properties of the position and direction of the emitting sound, in which four factors, such as the stimulus type and emission-time interval might affect their capacity to identify the stimuli. Additionally, the identification performance of the evacuee for the emitting sequences along the straight and bent lines was considered. Subsequently, we considered whether the evacuee could follow the emitting sound on a set of loudspeakers in sequence. Furthermore, we demonstrated that the proposed guidance system using the sound provided a more detailed evacuation route for evacuees.

The remainder of this paper is organized as follows. Section 2 presents the advantages of the proposed evacuation guidance system that emits sound stimuli sequentially. Section 3 summarizes properties of auditory recognition for the emitting sound stimuli based on our previous research [6]. Section 4 describes the subjects' ability to follow the sequence of the emitting sound based on experiments and discusses the practicality and feasibility of the proposed evacuation guidance systems. Finally, the usefulness of a sound-based guidance system proposed in this paper is summarized in Section 5.
