Hoverfly Brains Mapped To Detect the Sound of Distant Drones

A drone is seen in the sky as Chinese drone maker DJI holds a
demonstration to display an app that tracks a drone's registration and
owner in Montreal, Canada, November 13, 2019. REUTERS/Christinne
Muschi
A drone is seen in the sky as Chinese drone maker DJI holds a demonstration to display an app that tracks a drone's registration and owner in Montreal, Canada, November 13, 2019. REUTERS/Christinne Muschi
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Hoverfly Brains Mapped To Detect the Sound of Distant Drones

A drone is seen in the sky as Chinese drone maker DJI holds a
demonstration to display an app that tracks a drone's registration and
owner in Montreal, Canada, November 13, 2019. REUTERS/Christinne
Muschi
A drone is seen in the sky as Chinese drone maker DJI holds a demonstration to display an app that tracks a drone's registration and owner in Montreal, Canada, November 13, 2019. REUTERS/Christinne Muschi

For the first time, Australian researchers have reverse engineered the visual systems of hoverflies to develop drones capable of detecting other drones' acoustic signatures from almost four kilometers away. The research was published in the Journal of the Acoustical Society of America.

Autonomous systems experts from the University of South Australia (UniSA), Flinders University and defense company Midspar Systems say that trials using bio-inspired signal processing techniques show up to a 50 percent better detection rate than existing methods.

Hoverflies have a superior vision that can detect visual signs in complex landscapes. The researchers worked under the assumption that the same processes which allow small visual targets to be seen amongst visual clutter could be redeployed to extract low volume acoustic signatures from drones buried in noise.

By converting acoustic signals into two-dimensional 'images' (called spectrograms), researchers used the neural pathway of the hoverfly brain to suppress unrelated signals and noise, increasing the detection range for the sounds they wanted to detect.

Using their image-processing skills and sensing expertise, the researchers made this bio-inspired acoustic data breakthrough, which could help combat the growing global threat posed by IED-carrying drones, including in Ukraine.

“Bio-vision processing has been shown to greatly pick up clear and crisp acoustic signatures of drones, including very small and quiet ones, using an algorithm based on the hoverfly's visual system,” said UniSA Professor of Autonomous Systems and lead author Anthony Finn in a report.

“Unauthorized drones pose distinctive threats to airports, individuals and military bases. It is therefore becoming ever-more critical for us to be able to detect specific locations of drones at long distances, using techniques that can pick up even the weakest signals. Our trials using the hoverfly-based algorithms show we can now do this," noted Finn, who have high hopes for their new technique.



One Man Gored, 7 Others Bruised in Spain's Bull Running Festival

'Mozos' or runners take part in the second Running of the Bulls during the Sanfermines festival in Pamplona, Spain, 08 July 2025. The San Fermin festival runs until 14 July 2025. EPA/Daniel Fernandez
'Mozos' or runners take part in the second Running of the Bulls during the Sanfermines festival in Pamplona, Spain, 08 July 2025. The San Fermin festival runs until 14 July 2025. EPA/Daniel Fernandez
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One Man Gored, 7 Others Bruised in Spain's Bull Running Festival

'Mozos' or runners take part in the second Running of the Bulls during the Sanfermines festival in Pamplona, Spain, 08 July 2025. The San Fermin festival runs until 14 July 2025. EPA/Daniel Fernandez
'Mozos' or runners take part in the second Running of the Bulls during the Sanfermines festival in Pamplona, Spain, 08 July 2025. The San Fermin festival runs until 14 July 2025. EPA/Daniel Fernandez

A man was gored and seven others lightly injured on Tuesday, the second day of Pamplona's San Fermin festival in which thousands of people line the medieval city's narrow streets for the centuries-old tradition of running with bulls.

The man who was gored, identified only as being older than 25, was injured by a bull horn under his right armpit, a spokesperson for the city emergency services said.

"At this time, he is under observation but is in stable condition," she told reporters.

The seven others suffered bruises and contusions, some in the shoulder or head, Reuters reported.

In the festival's "encierros", or bull runs, fighting bulls are set loose in the streets and then race to reach the bullfight arena. Hundreds of aficionados, many wearing traditional white shirts with red scarves, run with them.

On Tuesday morning, one of the bulls stopped in the middle of his run, and charged the runners for several tense minutes.

The festival, which gained international fame from Ernest Hemingway's 1926 novel "The Sun Also Rises", lasts for one week in early July.

Participants are occasionally gored at the hundreds of such bull-running fiestas in Spain every year. Other injuries are common. At least 16 runners have lost their lives at the Pamplona festival down the years, the last in 2009.

As well as the morning bull runs and afternoon bullfights, the San Fermin festival features round-the-clock singing, dancing and drinking by revelers.
There are also religious events in honor of the saint.