Zvook covers Ukraine’s skies for under €50 million. Now, it has started testing hydrophones underwater

Ukrainian firm Zvook, renowned for its acoustic sensors covering Ukraine's airspace at a cost-effective €50 million, has now ventured into the underwater domain. The company, focusing on drone and missile detection, is currently testing hydrophones to identify vessels and other underwater entities via sound, as announced on LinkedIn.

Zvook's system is passive, emitting no sound, unlike traditional sonar, which sends acoustic waves into the water and listens for their return. The principle of passive listening, where the environment's existing sounds are utilized, is familiar to Zvook from its aerial operations. However, underwater conditions present unique challenges, including altered sound propagation, background noise, reflections, and varying acoustic signatures.

Zvook's current focus is on gathering real-world data to determine which objects can be reliably detected and classified, as well as identifying practical uses for a distributed passive underwater acoustic system. Potential applications include maritime security, vessel awareness, port protection, and the safeguarding of critical underwater infrastructure.

The company is also seeking commercial joint testing with defense organizations, maritime operators, and infrastructure owners. Zvook frames this shift as continuity rather than a new endeavor, emphasizing the common principle of passive listening across domains. The company asserts that their approach—listening to the sky, detecting underwater objects—remains the same: always listening, emitting nothing.