Tired commuters could be subjected to hi-tech adverts while resting their heads against train carriage windows.
An advertising agency has tested the technology and says it could soon be in use around the world.
It uses a technique known as bone conduction, which is also found in some hearing aids and in Google’s wearable computer Glass.
A small gadget sends out high-frequency vibrations through the window. “When you lean against the glass the vibration is transmitted via the skull into your brain and turned into sound,” said BBDO, the agency behind the trial in Germany. “The message is heard without acoustic signals travelling through the ear.”
The ads are only heard by people resting their heads against a window with the transmitter attached.
But commuters on a YouTube video titled Talking Window branded the move an invasion of privacy.
“If you’re tired on a train, the last thing you want is mind-invading adverts,” said one, while another asked: “What’s next? Companies beaming commercials into your dreams while you sleep?”
