Inventor David Schwartz says the device, still a prototype, could be a big advance for microphones because it picks up sound almost out of thin air. He suggests the “smokrophone” could make for a high-fidelity recording microphone, or a supersensitive spying device.

A smoke machine and a fan produce an even stream of smoke past a laser beam pointed at a sensor. Taking into a hole in the tube disturbs the smoke stream, affecting how the sensor picks up the laser beam.

Veteran microphone designer David Josephson of Josephson Engineering, says the concept is interesting, but may not yield much improvement in sound quality.

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