Lightbulbs: The Newest Spy Gadget?

Apparently lightbulbs can be used not just to help you see, but to help you hear, too!

This hack, apropos of its name “lamphone,” uses vibrations off hanging light bulbs to eavesdrop on conversations up to 100 feet away!  The only equipment needed is a laptop, a telescope and an electro-optical sensor… All of which can be purchased for under $1000, total.

Noises cause fluctuations in the air, which reverberate off of a hanging bulb.  Researchers tested this by setting three telescopes with differing lenses (10 cm, 20 cm and 35 cm) 80 feet away from an office using a 12-watt LED bulb.  They placed a Thorlabs PDA100A2 electro-optical sensor over the eyepiece of the telescope, and each time there was noise in the office, the vibrations were reflected by the bulb and then picked up by the sensor on the telescope.

After the sensor picked up the vibrations, they used an analog-to-digital converter to convert the signals into digital information that was then put through a noise-filtering program, and used Google Cloud Speech API, as well as song-identifying apps (think SoundHound) to convert the digital sounds back into human speech.  

This method allowed researchers to identify the Beatles’ song “Let it Be” and Coldplay’s “Clocks,” as well as Trump’s “We will make America great again” speech.

They also noted that while this experiment was performed 80 feet from the bulb, it would be simple to increase the range by simply using better equipment.

The Takeaway

It might be a bit scary to think about the implications of “Lamphone,” thinking someone could successfully and covertly spy on you using only your lightbulb. Fortunately, there are some relatively simple ways to thwart a would-be “Lamphone” invader.”

  • Get rid of all hanging bulbs – Not exactly practical but definitely effective
  • Reduce the brightness of the bulb – The less light there is to be recorded by the sensor, the harder it is to convert
  • Use heavier bulbs – The heavier the bulb, the less it vibrates
  • Turn off your lights and/or close your curtains

There are also a number of limitations; for example, the spy has to be at the right place at the right time, while you are talking with your lights on, so it’s important to be aware.

If you aren’t sure if your physical security is up-to-snuff, you can always give us a call at 919-422-2607.  Or schedule a free consultation online.

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