Fluorescent lamps (don't) have ears

The author, who previously worked in technical surveillance countermeasures, tests a decades-old claim that fluorescent lamps can be used for eavesdropping by detecting sound-induced luminosity changes in the glowing gas. Using high-speed photography and a powerful nearby sound source, the author conducted an experiment to determine whether sound waves could produce detectable visual artifacts in fluorescent tube emissions. The test represents a practical investigation into whether this theoretically plausible but physically questionable surveillance technique actually works in practice.