BeephoniX bets on acoustic intelligence to counter drone threats
Dutch spin-off turns hearing-science expertise into a passive, AI-driven sensor for real-time drone detection.
Published on November 24, 2025
Beephonix at Blue Magic Netherlands, © Nadia ten Wolde
Bart, co-founder of Media52 and Professor of Journalism oversees IO+, events, and Laio. A journalist at heart, he keeps writing as many stories as possible.
Detecting and neutralizing drones has been a concern in defense and security for years. As incidents increase and more people are affected, the search for a solution becomes more urgent. So when air traffic at Eindhoven Airport was halted for two hours this weekend due to unknown drones (and similar incidents caused unrest around the Volkel and Kleine Brogel military bases last week), the Minister of Defense responded immediately. “Disruption of air traffic with drones is unacceptable. So we are taking action against this,” said outgoing Minister Brekelmans.
It is not known how many drones were seen around the airport. It is also unclear who was controlling the drones. Well, how do you detect and track small, inexpensive, hard-to-spot drones in complex environments? Good question, but a few days earlier, literally a stone's throw from Eindhoven Airport, two Dutch startups formulated their answer to State Secretary for Defense Gijs Tuinman. Beephonix and Fiducial, both present at the Blue Magic Netherlands event in Eindhoven last week, explained their concrete solutions there. In this article, we will discuss BeephoniX's acoustic intelligence; click here for the story of Fiducial.
BeephoniX originated as a spin-off of the hearing science group at Radboud University and is currently based in Utrecht. “For us, it's all about acoustic intelligence, which we use to redefine airspace security,” CEO Klaas-Jan Kakebeeke told the audience. With the rapid spread of semi-military drones, smuggling drones, and commercially available quadcopters, “the threat is increasing,” he noted. “Are we really protected? Not yet sufficiently.”
No silver bullet, but a missing layer
Radar struggles with very small drones. RF systems fail when operators fly in silent mode. Optical sensors are blinded in fog, darkness, or urban clutter. That’s where BeephoniX sees room for its specialty.
“There is no silver bullet to counter-UAS,” Kakebeeke said. “Acoustics doesn’t replace radar or RF, but it adds a layer those systems don’t have.”
Their sensor, the BeephoniX M2, is a 40-centimetre, fully passive acoustic array containing 151 MEMS microphones. Using real-time beamforming, AI-based signal processing, and classification algorithms, it detects, localises, tracks, and identifies Class I–II drones — even in GPS-denied or visually obstructed terrain.
Because it emits no signal of its own, the system is especially attractive for special forces or covert operations. “It’s fully passive, so it can be useful in cases where you don’t want to reveal your position,” Kakebeeke said.
Surprising accuracy and long-range FPV detection
In a recent demo with the Dutch military, the M2 detected FPV drones at distances of 600 to 900 metres, without visual line of sight. Commercial drones such as the DJI Mavic 4 were picked up at 200–300 metres with a single sensor.
Larger, noisier drones such as Shahed-type models, whose use in Ukraine has spawned an entire cottage industry of open-source acoustic datasets, could potentially be detected at 1.5 km, according to early modelling.
Accuracy in direction finding currently sits at 1–2 degrees, which becomes powerful when sensors operate in a mesh. “If we place them in a network, we can create a dome covering an area,” Kakebeeke explained.
From hearing aids to battlefield sensing
BeephoniX’s roots in audiology matter more than you’d think. The startup’s beamforming and noise-cancellation algorithms originate from work on solving “the cocktail-party problem”, distinguishing meaningful signals in noisy environments. For drones, the principle is similar: recognise a rotor signature hidden in environmental clutter.
The company now employs nine specialists (embedded software engineers, ML experts, and signal-processing scientists) and plans to double headcount next year. A NATO-standard SAPIENT interface and additional APIs ensure the sensor can plug into existing situational-awareness systems.
BeephoniX sees itself not as a standalone counter-drone solution, but as a data layer feeding radar, RF, EO/IR, and command-and-control platforms. “We sell sensors, but in the end we sell data,” Van den Brink said. “Situational awareness depends on combining sensor modalities.”
A growing commercial pipeline
The startup is preparing 10–15 projects for 2025, representing €1.2–1.5 million in early revenue. One major pilot will run at the Port of Amsterdam, where the M2 will complement radar and camera networks to detect drone movement over water and industrial sites.
Another goal is vehicle-mounted detection, which requires filtering out engine noise through training data. Special-forces units have also expressed interest in a smaller 20-cm version of the array.
Long-term, BeephoniX expects the same hardware could detect artillery fire or gunshots using low-frequency signatures, broadening its scope beyond drones.
Raising up to €5 million
To scale, the company is seeking €5 million in investment to strengthen its AI team, expand classification datasets, reduce false positives, and build a small specialised sales unit, including a military advisor. “We understand the technology, but we’re still learning the defence language,” Kakebeeke admitted.
As drone incidents continue to disrupt civilian and military airspace, from Eindhoven Airport to Volkel and Kleine Brogel, Europe is scrambling for layered, affordable detection options. BeephoniX believes sound will be part of the answer.