Have you ever leaned your head against a train window to get a closer look at the passing scenery? Or maybe rested your head against your bus window to have a quick nap? How would you feel if a mysterious voice started selling broadband & TV bundles to you while you were doing it?

That’s the premise behind new technology that has been developed by advertisers BBDO Germany for Sky Deutschland. The latter are still deciding whether they’ll use the device for a full ad campaign for their mobile app following ‘positive’ trials.

A transmitter placed on the window of a train passes vibrations through the skull. These are picked up by the ear bones and translated to sound by the brain. The result is a message only the person leaning against the window can hear.

Similar ‘bone conduction’ technology is used in hearing aids and headphones. The forthcoming Google Glass will also use a variation on the idea to ensure messages transmitted to the wearer are almost completely inaudible to everyone else.

A spokesperson for BBDO told BBC “some people don´t like advertising in general. But this is really a new technology. [It might] not only be used for advertising, but also for music, entertainment, mass transport information, weather reports and so on."

However, the general public might not be ready to accept this new form of media just yet. User comments from a video introducing the technology include “Ugh. We need ad blocker for our brains” and “remind me to carry a screwdriver to rip this off the window.”

The so-called “talking window” shows no sign of expanding beyond German trains just yet.