The outdoor billboard that displays an ad for Paranormal State, a ghost-themed series premiering on A&E this week, uses special technology to transmit sound so close to you that you think its inside your head. As you walk by, the sound of a woman's voice whispers "Who's that? Who's there?... It's not your imagination." Advertisers describe it as a "chilling message."

The technology is created by Holosonic; the device is effectively an "audio spotlight" that can project sound literally right into your ears. Previously, this technology had been used in places like museums or libraries; it creates an isolated experience while not disturbing those in the general area.

This video highlights the technology of audio spotlighting.