The people who have to commute to work on public transport early in the morning, you know how much sometimes want to sleep. And the pillow can be any rest for the head, in particular, and the ordinary window. For such cases, invented a device called Tаlking Windоw. He invented in order to have passengers not been able to sleep through my stop.
Tаlking Window is a simple device that attaches to conventional Windows in public transport. It is almost invisible to passengers. But such a device would be an additional means of warning people about the approaching stops.
The fact that the Talking Window glass transmits light high frequency vibrations that cannot be heard by ear. But they will be fairly noticeable, if a person touches the window with his head and, for example, sleep.