This is kind of disturbing:

The billboard uses technology manufactured by Holosonic that transmits an "audio spotlight" from a rooftop speaker so that the sound is contained within your cranium. The technology, ideal for museums and libraries or environments that require a quiet atmosphere for isolated audio slideshows, has rarely been used on such a scale before. For random passersby and residents who have to walk unwittingly through the area where the voice will penetrate their inner peace, it's another story.

I predict a lawsuit at some point.