EKHO Technologies is a French deeptech company developing passive acoustic drone detection technology for critical infrastructure, defence and security applications. The system is built as a counter-UAS (C-UAS) sensor layer: an RF-independent drone detection system based on distributed acoustic sensors and local, edge processing, developed in France as part of a wider push for sovereign European defence technology.
Acoustic drone detection identifies the presence of an unmanned aircraft from the sound it produces (primarily the aerodynamic and mechanical noise of its motors and propellers) rather than from any signal the drone itself transmits.
Unlike radar, which sends out a signal and analyses its echo, or RF detection, which listens for the radio link between a drone and its operator, passive acoustic sensing simply listens to the ambient sound environment without emitting anything itself.
EKHO is not built to replace radar, RF detection, or the optical and thermal systems already deployed on a sensitive site. Each of these technologies has its own strengths and its own blind spots: radar performance depends on propagation conditions, optical and thermal sensors depend on visibility and line of sight, and RF detection depends on the existence of an exploitable radio link between the drone and its operator.
Passive acoustic sensing adds a further detection channel, as part of a sensor-fusion approach, reducing the combined blind spots of a protection system rather than substituting for any single layer of it.
Some drone architectures reduce or eliminate the radio signature an RF system is built to intercept: pre-programmed autonomous flight paths that need no real-time command link, or fibre-optic wire-guided control, which carries commands over a physical cable instead of a radio wave.
In both cases, an RF detection system has nothing to intercept, however sensitive it is. The drone remains a physical object in motion, though, and its motors and propellers still produce a characteristic sound. This is the signature passive drone detection is built to identify.
An EKHO sensor carries a microphone array in continuous passive listening. It isn't waiting for a specific signal from a transmitter: it constantly analyses the surrounding sound environment for an acoustic signature characteristic of a drone's motors or propellers.
The captured signal is processed locally using signal-processing techniques (frequency-domain analysis) combined with classification models, to separate a drone signature from ambient noise (road traffic, wind, industrial activity, wildlife). This processing runs on the EKHO Core unit, cable-connected to the sensors.
When a sensor detects a matching signature, the EKHO Core computes an azimuth estimate: the direction the sound was heard from. When several sensors deployed across a site pick up the same source, comparing their observations refines the drone's estimated position through triangulation.
The value of the approach grows with the number of sensors deployed. EKHO is designed to work as a network of distributed acoustic sensors, each one reporting its observations to the EKHO Core over a wired RJ45 Ethernet connection. The whole site is covered by multiple listening points instead of a single sensor, improving both coverage and localisation quality.
Sensors connect to the EKHO Core over wired Ethernet (RJ45), and the EKHO Core connects to the supervision console over the site's local network (LAN). No cloud, no Wi-Fi and no internet connection are required for the detection function itself: the analysis happens on site, on hardware installed at the customer's premises.
This approach targets first the sites with the most direct exposure to the drone threat: Seveso-classified sites, port infrastructure, industrial sites and other critical infrastructure, particularly in dense industrial areas such as Fos-sur-Mer, the Étang de Berre and Marseille in southern France. EKHO is being developed as a critical infrastructure protection layer alongside the security measures already in place on these sites; the system is currently a functional prototype, undergoing field validation campaigns.
Sensors, local processing and the supervision console, in detail.
Learn more about EKHO's detection architecture →