Mike Harrison

Visualizing the invisible with microphone arrays The Crysound Pocket Acoustic Imaging Camera represents a massive shift in high-end diagnostic hardware. Traditionally, seeing sound required industrial gear costing tens of thousands of dollars. This device uses a central optical camera surrounded by a sophisticated microphone array. By leveraging advanced digital signal processing, it overlays a heat-map-style visualization of sound sources onto a real-time video feed. It transforms invisible acoustic energy into actionable visual data, much like a thermal camera does for heat. Hunting corona discharge and ultrasonic leaks Testing the unit reveals surprising sensitivity. In a garage setting, the camera instantly locked onto the corona discharge of an ion generator from ten meters away. This is a critical application; electrical distribution networks use this technology to find failing insulators or high-voltage leaks that are nearly silent to the human ear. The camera also identified the high-frequency signature of an ultrasonic atomizer and the faint whine of a switch-mode power supply inside a sealed electricity meter. For industrial maintenance, this means pinpointing compressed air leaks or failing bearings across a noisy factory floor without shutting down operations. Professional precision at hobbyist prices The most disruptive element is the price point. A comparable Fluke acoustic imager typically retails around £20,000. The Crysound alternative delivers roughly 95% of that utility for 5% of the cost. While the demonstrator unit lacks internal video recording—requiring a physical jig to capture the screen via smartphone—the core sensing technology remains robust. It makes a niche tool, once reserved for massive utility companies, accessible to small machine shops and dedicated hardware enthusiasts. Navigating the physics of acoustic imaging Operating this gear requires more than just pointing and shooting; you have to understand acoustic physics. Low-frequency sounds are omnidirectional and tend to fill a room, while high-frequency and ultrasonic sounds are highly directional. The device allows for manual frequency filtering to isolate specific equipment noise, though the auto-mode handles ambient rumble effectively. Like thermal imaging, users must account for reflections. Sound bounces off hard surfaces, which can occasionally create ghost images on the display if the operator isn't careful. Despite these nuances, the ability to "see" a gas leak or a failing capacitor is a massive diagnostic advantage.