Norwegian tech uses audio beacons to get people out of smoky tunnels

If you're in a road tunnel that suddenly gets filled with smoke due to a vehicle fire, it can be very difficult knowing which way to head. That's where EvacSound comes in, as it uses audio beacons to guide people to safety.

Many road tunnels are located in remote, mountainous regions. As a result, rescue workers may take some time to reach them in the event of a fire. And even once the rescuers do arrive, their path may be blocked by the burning vehicle(s) within the tunnel. This means that it's very much for the best if drivers within the tunnel can walk out on their own, as soon as possible.

EvacSound should hopefully make that happen.

The system is being designed at Norway's SINTEF research institute, by a team led by Tron Vedul Tronstad. It consists of a series of loudspeakers placed along the length of a tunnel, that sequentially emit sounds which guide people away from the fire and towards the unblocked end of the tunnel. Importantly, the sounds are non-verbal, so that language shouldn't be a barrier.

In a test of the system, 30 volunteers were taken to a tunnel in Trondheim, Norway, then fitted with taped-over goggles that simulated the low visibility caused by smoke. They were subsequently tasked with finding their way out of that tunnel – they did so first with and then without guidance from the audio beacons, that were coming from speakers placed at 20-meter (66-ft) intervals. To make things more realistic, the sound of smoke-clearing fans was also added.

It was found that while the system was definitely effective at helping the test subjects to quickly get out of the tunnel, it was most effective with younger participants. This was likely due to the hearing loss which people experience as they get older, suggesting that EvacSound may work best if combined with visual indicators such as sequentially flashing lights.

Source: SINTEF