Search and Rescue drones to get voice-detecting superpowers

It is not about drones lurking in the sky on the lookout (or is it a listen-out) for telltale human voices screaming into the void, before stealthily moving for the kill.


It is search and rescue adding a feature that could help a lot of humans lost in the woods or trapped in the aftermath of a disaster situation, desperately hoping for somebody to notice them in time and whisk them away to safety.

Human voice recognition. That – according to the Washington Post (story behind a paywall) – is the subject of advanced research by engineers at Germany’s Fraunhofer FKIE institute, who’ve built a drone prototype designed to find people by detecting human screams and keep a specially designed ear for other signs of distress.

One of the lead engineers, Macarena Varela, says the gadget would be ideal for post-disaster scenarios, such as earthquakes, hurricanes and wildfires.

“Drones can cover a larger area in a shorter period of time than rescuers or trained dogs on the ground,” the Post quoted Varela saying, at an annual conference hosted by the Acoustic Society of America. “If there’s a collapsed building, it can alert and assist rescuers. It can go places they can’t fly to or get to themselves.”

To us, it is sad that the angle many have chosen to take in reaction to this potential discovery, is that of being creeped out by the potential abuse of a technology which is certainly not being developed for nefarious purposes.

Take an example of the December 2020 landslide in Norway, for example, which resulted in the largest search and rescue drone operation in Europe. How vital would the eaves dropping drone have been then, for somebody who was trapped in the snow and shouting their lungs out to be rescued?

Would any of the more than 613 people (at the last count) on this interactive map, rescued by a drone from the deathly hallows have given two hoots about the flip side of a drone detecting their voice from far, far away at a time when they needed anything that breathed oxygen – or didn’t – to find them and get help immediately?

We know how drone technology has been helpful in disaster and distress situations, when the autonomous birds have flown into areas too dangerous for humans to tread in without prior reconnaissance and assessed the scale of the damage; seek out where the potential danger lurks; even going to the extent of seeking signs of life through activating thermal aerial imaging.

Would adding human voice detection capabilities to the drone be such a terrible idea, when they already do so much?

In training the voice recognition software, the engineers are said to have recorded themselves screaming, tapping and creating other noises that might be a sign of people in trouble. Then, they analysed each sound frequency to find common “signatures” and used those to train artificial intelligence software.

They also worked to filter out the noise created by drone rotors and other environmental sounds, Varela said.

Once the software part was complete, they assembled a system of tiny digital microphones to provide “precise” angles for where sound is coming from. Digital microphones like the ones found in smartphones and hearing aids were used because they don’t require as much bulky hardware as analogue or traditional microphones, the researchers said.

The team placed the cluster of microphones under a drone and used signal processing techniques that enabled it to track where human noises are coming from. The system also enhanced the volume and clarity of the speech. So far, they have conducted successful “open field experiments,” finding that the drone can estimate a victim’s location within a few seconds of picking up sound, Varela says.

In a demonstration video, the drone is shown hovering above the ground before pivoting in the direction of a researcher making noises and calling for help on the ground.

“We have already succeeded in angularly detecting and locating impulsive sounds very precisely … with the presence of drone noise,” Varela said.

The engineers are working on installing a higher frequency microphone to a drone to acquire more audio sound signals and pick out up noises hundreds of metres away.

In the real world, the victim location data might one day be sent wirelessly to emergency crews carrying a tablet.

But there is no date yet for the arrival of this technology.


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