AUDITORY GUIDANCE METHOD AND SYSTEM

Abstract

An auditory guidance system is installed along a predefined pathway between an initial location and a target location. The auditory guidance system comprises a plurality of nodes arranged at intervals along the predefined pathway. A first node of the plurality of nodes is a closest node to the initial location and a last node of the plurality of nodes is a closest node to the target location. Each node of the plurality of nodes comprises two directional sound generators. Each of the two directional sound generators are configured to emit sound in a predetermined direction. The two directional sound generators within each node are pointing in opposite directions along the predefined pathway.

Claims

1. An auditory guidance system for installation along a predefined pathway between an initial location and a target location, comprising a plurality of nodes arranged at intervals along the predefined pathway, wherein a first node of the plurality of nodes is a closest node to the initial location and a last node of the plurality of nodes is a closest node to the target location, and wherein each node of the plurality of nodes comprises two directional sound generators each of the two directional sound generators being configured to emit sound in a predetermined direction, wherein the two directional sound generators within each node are pointing in opposite directions along the predefined pathway.

2. The system of claim 1, wherein the two directional sound generators each comprise loudspeakers with small apertures arranged into an array.

3. The system of claim 1, wherein each of the two directional sound generators in each node is configured and controlled via a control system to emit a sound pulse of predefined characteristics.

4. The system of claim 3, wherein the characteristics comprise a duration, a pitch, and a volume.

5. The system of claim 3, wherein the sound pulses comprise a sound of bell chimes or a sound of footsteps on pavement.

6. The system of claim 3, wherein the system is configured to emit a same sound pulse from all of the nodes.

7. The system of claim 1, wherein the nodes are configured to be activated in a sequence, from the initial location and towards the target location.

8. The system of claim 1, wherein the two directional sound generators in each node are controlled to emit a same sound pulse at a same time, or are controlled to emit sound pulses in a desired sequence.

9. The system of claim 1, wherein each of the two directional sound generators is configured to emit a sound pulse towards the initial location, in a sequence from the directional sound generator in the first node to the directional sound generator in the last node, each sound pulse emission being interrupted by a constant time interval.

10. The system of claim 4, wherein the duration is constant.

11. An evacuation system in a tunnel or other confined space, comprising: an auditory guidance system for installation along a predefined pathway between an initial location and a target location, comprising a plurality of nodes arranged at intervals along the predefined pathway, wherein a first node of the plurality of nodes is a closest node to the initial location and a last node of the plurality of nodes is a closest node to the target location, wherein each node of the plurality of nodes comprises two directional sound generators each of the two directional sound generators being configured to emit sound in a predetermined direction, wherein the two directional sound generators within each node are pointing in opposite directions along the predefined pathway, and wherein the target location comprises an emergency exit or another opening out of the tunnel or confined space.

12. An auditory guidance method, for guiding at least one individual along a predefined pathway from an initial location to a target location, comprising: emitting directional sound pulses from a plurality of nodes arranged at intervals along the predefined pathway between the initial location and the target location, the directional sound pulses being emitted in a sequence at time intervals such that each node emits a directional sound pulse towards the initial location, wherein a second node emits a sound pulse at a time interval following the emission of a sound pulse from a first node, wherein, for each of a third node and one or more subsequent nodes, the respective node emits a sound pulse at the time interval following the emission of a sound pulse from a previous node until a last node has emitted a sound pulse, wherein the sequential emission of sound pulses from the same side directional sound generators creates a spatial effect and an illusion of a sound travelling towards the target location and thus encourages the individual to follow the sequentially emitted sound pulses.

13. The method of claim 12, wherein the time interval is constant.

14. The method of claim 12, wherein the pathway is inside a tunnel or other confined space, and the target location comprises an emergency exit or another exit from the tunnel or other confined space, and wherein the sound pulse duration is determined such that the sound pulse duration is significantly shorter than the reverberation time for the tunnel or other confined space.

15. The method of claim 12, wherein the method is executed in multiple segments of nodes, either simultaneously or at different intervals.

16. The method of claim 12, wherein the auditory guidance system installed along the predefined pathway between the initial location and the target location comprises the plurality of nodes and performs the emitting step.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] These and other characteristics of the invention will become clear from the following description of embodiments of the invention, given as non-restrictive examples, with reference to the attached schematic drawings, wherein:

[0020] FIG. 1 is a schematic illustration of an embodiment of the auditory guidance system according to the invention; and

[0021] FIG. 2 is a schematic illustration of an embodiment of the auditory guidance method and system according to the invention;

[0022] FIG. 3 is a schematic illustration of another embodiment of the auditory guidance system according to the invention;

[0023] FIG. 4 is a schematic illustration of another embodiment of the auditory guidance method and system according to the invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0024] The following description may use terms such as “horizontal”, “vertical”, “lateral”, “back and forth”, “up and down”, “upper”, “lower”, “inner”, “outer”, “forward”, “rear”, etc. These terms generally refer to the views and orientations as shown in the drawings and that are associated with a normal use of the invention. The terms are used for the reader's convenience only and shall not be limiting.

[0025] Referring initially to FIG. 1, the invented auditory guidance system comprises a plurality of nodes 2 arranged along a predefined pathway 1. The predefined pathway 1 may be a roadway inside a tunnel or any other surface in a confined space (such as a mine shaft, rail tunnel, corridor) or room. The predefined pathway 1 may also be in the open, out of doors. The nodes 2 are arranged at intervals along the pathway 1, on a wall along the pathway, in a ceiling above the pathway, or on another suitable support. It should be understood that there may be several more nodes than what the figure indicates, for example in a long tunnel. The distance between the nodes may be known or be determined by the system, for example as described by EP 3 629 604 A1. The distance between the nodes may for example be between 10 and 30 meters, but this invention shall not be limited to this interval.

[0026] In FIG. 1, the predefined pathway 1 is inside a confined space having walls 10 with side exits (e.g. emergency exits) 3, a fire extinguisher 5 and an emergency phone 6, and the nodes 2 are connected to one of a plurality of switches 7 and controlled by a control system 8. However, the invention shall not be limited to this configuration.

[0027] Reference number 4 denotes a target area for the auditory guidance performed by the nodes 2. A target area may for example be at a tunnel opening or the exit from a corridor or other confined space, or one of the emergency exits 3. These areas 4 and exits 3 will therefore in the following also be referred to as “target locations”.

[0028] Each node 2 comprises two directional sound generators 9a,b that each are configured to emit sound in a predetermined direction. The directional sound generators may be assembled in a common housing, but not necessarily. In the embodiment illustrated in FIG. 1, the two directional sound generators 9a,b are pointing along the predefined pathway 1 and in opposite directions.

[0029] The directional sound generators 9a,b may be loudspeakers, for example loudspeakers with small apertures arranged into an array. The left and right facing directional loudspeakers in each node provides for optimal use of acoustic energy. For example, referring to FIG. 2, a person located between two nodes 2.sub.1, 2.sub.2 will perceive the sound generated by the right-hand sound generator 9a.sub.1 as being substantially (e.g. more than 12 dB) lower than the sound generated by the left-hand sound generator 9b.sub.1 of the same node 2.sub.1.

[0030] The use of such directional loudspeakers contributes to reducing the reverberation effects that may be pronounced in confined spaces, such as tunnels. This is an advantage over the prior the non-directional loudspeakers of the prior art PA systems, where reverberation effects may last several seconds and render precise auditory guidance impossible.

[0031] Each sound generator 9a,b in each node 2 is configured and controlled (e.g. via the control system 8) to emit a sound pulse A with predefined characteristics (e.g. duration, pitch, volume). Examples of emitted sound pulses are bell chimes, sound of footsteps on pavement, but a number of other sounds are conceivable. The system may be configured to emit the same sound pulse from all the nodes, or the sound pulse characteristics and type may be different between the nodes. The nodes are configured to be activated in a sequence, from an initial location L and towards the target location 4.

[0032] Sound generators 9a,b in each node 2 may be controlled to emit the same sound pulse at the same time, or to emit sound pulses in a desired sequence, as will be explained in the following, with reference also to FIGS. 2-4.

[0033] If it is desirable to guide one or more individuals P away from a location L, where for example a fire E or other critical event may have occurred, to a target location (e.g. a tunnel opening 4 or an emergency exit 3), the invented auditory guidance system may be operated in a manner described in the following.

[0034] A node 2.sub.1, which is the closer one to the individual P (and therefore for the purpose of illustrating the method is designated as a first node), is activated such that its sound generator 9a.sub.1 facing the initial location L emits a directional sound pulse A. Then, after a time interval Δt, a subsequent, second, node 2.sub.2, which is adjacent to the first node 2.sub.1 but farther away from the initial location L, is activated such that its sound generator 9a.sub.2 facing the first node 2.sub.1 emits a directional sound pulse A. Following another time interval Δt, a third node 23, which is adjacent to the second node 2.sub.2 but closer to the desired location 4, is activated such that its sound generator 9a3 facing the second node 2.sub.2 emits a directional sound pulse A. FIG. 2 illustrates three nodes between the initial location L and the target location 4, but it will be understood that the system may comprise fewer (at least two) or more nodes, e.g. nodes 2.sub.1-n. For example, FIG. 3 illustrates 13 nodes 2 arranged along a passageway 1. It should also be understood that the other sound generators (i.e. 9b.sub.1-n) will be activated in a similar manner if it is desirable to guide individuals in the opposite direction along the pathway.

[0035] For an individual P between nodes 1 and 2, the sound pulse A emitted from the sound generator 9a.sub.1 in the first node 2.sub.1 will be perceived as being at a lower level than the sound pulse A emitted from the sound generator 9a.sub.2 in the second node 2.sub.2. This directionality assures that there is reduced perception of incoming sound from the node 2.sub.1 compared to perception of departing sound from nodes 2.sub.2 and then 23. The sequential emission of sound pulses A from the same side directional sound generators 9a.sub.1-n in subsequent nodes 2.sub.1-n creates a spatial effect and an illusion of a sound travelling towards the target location 4. This encourages the individual to follow the sequentially emitted sounds pulses towards the target location. Optionally, the sound pulse emission may be interrupted at intervals by voice instructions such as “follow the sound to safety.” The directional effect helps remove ambiguity as to which way to go, and provides an imperative for moving in the desired direction, away from the initial location (e.g. a fire) and towards the target location.

[0036] The sound pulse duration t.sub.A and time interval Δt may be controlled or pre-programmed according to the specific environment. For example, if the pathway 1 is inside a tunnel og similar passage, the sound pulse duration t.sub.A is advantageously significantly shorter than the tunnel reverberation time. If, for example, the tunnel reverberation time is between 2 and 4 seconds, the sound pulse duration t.sub.A may preferably between 0.2 and 0.5 second, and the time interval Δt may be between 0.5 and 1 second. The sound pulse duration t.sub.A may be constant or may be different for each node.

[0037] If the target location (e.g. emergency exit 3 or tunnel opening 4) is far away from the initial location L, for example as illustrated in FIG. 3 (a total of 13 nodes), the delay from the first sound pulse is emitted from the first node 2.sub.1 and the last sound pulse is emitted from the last node 2n (in figure, n=13), may be unacceptably long. It may therefore be desirable to activate groups of nodes individually, for example at the same time. This is illustrated in FIG. 4, where an activation sequence corresponding to the one described above is shown as being be repeated on adjacent groups G of nodes. The pathway is thus divided into smaller segments and the sound level may be adjusted such that multiple segments G can play at the same time without being heard from another section. The number of nodes per segment will vary (depending on for example the distance between the nodes, acoustical properties of the environment, the sound to be used). These parameters may be measured (e.g. by microphones at or in the nodes) and the sound emission may be adjusted accordingly.

[0038] The invented auditory guidance method and system is particularly useful for evacuating individuals from a tunnel or other confined space when visibility is low or non-existing, for example in the event of a fire.