Auditory guidance method and system

An evacuation system in a tunnel, 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 wherein each of the two directional sound generators is configured to emit sound in a predetermined direction and includes loudspeakers with apertures arranged in an array, wherein the two directional sound generators within each node are pointing in opposite directions along the predefined pathway,
• wherein adjacent nodes of the plurality of nodes enable, at a location between the adjacent nodes, a perception that the sound generated by a right-hand sound generator of a node of the adjacent node as being substantially lower than the sound generated by a left-hand sound generator of the same node, and
• wherein the target location comprises an emergency exit or another opening out of the tunnel.

An auditory guidance method, for guiding at least one individual along a predefined pathway in a tunnel from an initial location in the tunnel to a target location in the tunnel, 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,
• wherein the target location comprises an emergency exit or another exit from the tunnel, and wherein the sound pulse duration is determined such that the sound pulse duration is significantly shorter than a reverberation time for the tunnel.