Skip to comments.Spies can eavesdrop by watching a light bulb’s variations
Posted on 06/13/2020 7:41:22 AM PDT by DUMBGRUNT
The list of sophisticated eavesdropping techniques has grown steadily over years: wiretaps, hacked phones, bugs in the walleven bouncing lasers off of a building's glass to pick up conversations inside. Now add another tool for audio spies: Any light bulb in a room that might be visible from a window.
Researchers from Israeli's Ben-Gurion University of the Negev and the Weizmann Institute of Science today revealed a new technique for long-distance eavesdropping they call "lamphone." They say it allows anyone with a laptop and less than a thousand dollars of equipmentjust a telescope and a $400 electro-optical sensorto listen in on any sounds in a room that's hundreds of feet away in real-time, simply by observing the minuscule vibrations those sounds create on the glass surface of a light bulb inside. By measuring the tiny changes in light output from the bulb that those vibrations cause, the researchers show that a spy can pick up sound clearly enough to discern the contents of conversations or even recognize a piece of music.
...The researchers found that the tiny vibrations of the light bulb in response to soundmovements that they measured at as little as a few hundred micronsregistered as measurable changes in the light their sensor picked up through each telescope.
As unlikely as being targeted by this technique is, it's also easy to forestall. Just cover any hanging bulbs, or better yet, close the curtains.
(Excerpt) Read more at en24.news ...
Just a hacked version of a decades old technique of using a laser to pick up vibrations off a window.
doubt if they can duplicate this with the LED bulbs.
Shoot back in the 60s they could listen in on cradled phones in a room due to the micro voltages created by the transducer.
Not at all. This is a passive method.
I suspect incandescent bulbs are required.
Shoot back in the 60s they could listen in on cradled phones in a room due to the micro voltages created by the transducer
And a few years later, the line powered transmitter.
Trim the antenna for your desired frequency on the am band.
They used to be ~ $2.00 each.
Simply installed in the network interface box outside the house.
Beat me to it.
Just a glass bulb needed and many LED are glass. Many are not and perhaps the plastic construction will not vibrate as much.
When the phone companies started adding that box (first heard about it in FL), future "Florida Man" types would mosey on up to snowbird houses, small phone in hand, plug the network side into the phone, and make 900 number sex calls.
How surprised were the Winter residents getting their sky-high phone charges on their monthly bill from their "Summerized" and unoccupied home.
I doubt this was available years ago when the Soviet army occupied Afghanistan, but there is a funny story about lights and spying.
The Chief of Station knew that the Sov. intel folks were keeping track of him by watching his window lights. He figured out a way to put a dummy in his place that would move its arms and head automatically and could be seen in silhouette through his office window. Reportedly it drove the Sovs mad because he was working so many hours.
While watching the Honeymooners for bare bulbs...I remembered this:
Breaking Into a Smart Home With A Laser - Smarter Every Day 229
Some of the set lightings look possibly lit from a bare bulb.
None where visible.
I read the article but the english seems to be a second language to the writer. BTW I had a booklet of electronics kits, must be back in the 1970’s that explained about the spying using window vibrations.
A laser microphone is a surveillance device that uses a laser beam to detect sound vibrations in a distant object. It can be used to eavesdrop with minimal chance of exposure.
The object is typically inside a room where a conversation is taking place and can be anything that can vibrate (for example, a picture on a wall) in response to the pressure waves created by noises present in the room. The object preferably should have a smooth surface for the beam to be reflected accurately. The laser beam is directed into the room through a window, reflects off the object, and returns to a receiver that converts the beam to an audio signal. The beam may also be bounced off the window itself. The minute differences in the distance traveled by the light as it reflects from the vibrating object are detected interferometrically. The interferometer converts the variations to intensity variations, and electronics are used to convert these variations to signals that can be converted back to sound.
Laser microphone for audio surveillance via window panes
>>The Chief of Station knew that the Sov. intel folks were keeping track of him by watching his window lights. He figured out a way to put a dummy in his place that would move its arms and head automatically and could be seen in silhouette through his office window. Reportedly it drove the Sovs mad because he was working so many hours.
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