They were even able to extract usable audio from videos of aluminium foil, the surface of a glass of water and even the leaves of a potted plant."
New York, Aug 6 - It may be hard to imagine that your favourite packet of potato chips or even a glass of water can serve as a microphone to catch a criminal.
But, this is not for researchers at the Massachusetts Institute of Technology (MIT) who have developed an algorithm to recreate sounds by analysing minute vibrations that sound makes on an object.
By pointing a video camera at a bag while audio was playing, researchers were able to detect distinct vibrations in the bag caused by sound.
Using their new algorithm, the team translated those vibrations and were able to reproduce the speech - despite the bag being 15 feet away and behind the soundproof glass.
When sound hits an object, it causes the object to vibrate. The motion of this vibration creates a very subtle visual signal that is usually invisible to the naked eye. People did not realise that this information was there, explained lead researcher Abe Davis from MIT in a press release.
The MIT team used a high-speed camera that could capture 2,000-6,000 frames per second from a bag of potato-chips.
The minute vibrations made by sound on the bag were analysed and by running an algorithm, the scientists were able to recreate the sounds in a laboratory.
They were even able to extract usable audio from videos of aluminium foil, the surface of a glass of water and even the leaves of a potted plant.
The discovery has many uses in law enforcement and forensics and could lead to the development of listening devices that do not need microphones, the MIT release added.