Light bulb vibrations yield eavesdropping data

[Jim__]

From TechXplore:

...

Israeli researchers report that they successfully tapped into speech and music inside an apartment simply by focusing on a light bulb.

In a paper published over the weekend, the researchers said all they needed were a telescope and a $400 optical sensor, which they used to measure barely perceptible light bulb vibrations triggered by either voices or music in the room.

The research team conducted the test by pointing a telescope situated in a bridge towards a light bulb in an apartment building 27 yards away. Capturing the vibrations from the bulb, they were able to reconstruct, with a fair degree of fidelity, "Let It Be" by the Beatles, "Clocks" by Coldplay and a snippet of a speech by President Trump.

"We show how fluctuations in the air pressure on the surface of the hanging bulb (in response to sound), which cause the bulb to vibrate very slightly (a millidegree vibration), can be exploited by eavesdroppers to recover speech and singing, passively, externally, and in real time," the researchers said.

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[erronis]

1. Interesting, but doubt it would work with LED or fluorescent/CFL or gas(xenon,etc.) bulbs.

Several facilities I worked in worried about vibrations in window glass, reflections off computer screens, changes in wattage in rooms, etc. Thus lots of shielding of various types. Expensive (and therefore lucrative) paranoia.

[Ilsa]

2. In the movie Eagle Eye, a despotic supercomputer in the DoD

had tried using the phones lines to eavesdrop, then something else. Ultimately, it read and learned the vibrations on the fluid surface of a cup of coffee in the room. That was fiction ten years ago. This story doesn't surprise me a bit.

Absolutely f'n scary.

[Warpy]

3. Picking up speech via window glass was done years ago.

I suppose the light bulbs are for when the windows are open and the flat's too high up for convenient eavesdropping via stethescope at the door.

[Jim__]

5. Yes, they talk about other methods of eavesdropping at the beginning of the video.

They emphasize that this method is real-time, passive, and external. They seem to think it has advantages even when the windows are closed.

[dutch777]

4. Window glass works the same way and is easier to access

This technology has been known and reportedly used for some time by sophisticated intelligence agencies. Of course you need to know what room your target conversation is in or you have some searching and sorting to do and you have to have clear line of sight to the window. Henry Kissinger and others were reported to use Chatterboxes when they were potentially exposed in places with windows, like hotel rooms and needed to have confidential conversations. Chatterboxes are sound generators that put out jumbled voice frequency noise so actual speech to anyone not immediate to the conversation just hears jibberish. Works on e-bugs too to some extent.