From today’s Globe and Mail:
“Strolling down the street in Manhattan, I suddenly hear a woman’s voice,” Clive Thompson writes in Wired magazine. “‘Who's there? Who’s there?’ she whispers. I look around but can’t figure out where it’s coming from. It seems to emanate from inside my skull. Was I going nuts? Nope. I had simply encountered a new advertising medium: hypersonic sound. It broadcasts audio in a focused beam, so that only a person standing directly in its path hears the message. In this case, the cable channel A&E was using the technology to promote a show about, naturally, the paranormal. I’m a geek, so my first reaction was, ‘Cool!’ But it also felt creepy.”
From an April 2007 article in the Boston Globe:
Court TV recently installed the “audio spotlight devices” in ceilings of bookstores to promote the network’s new murder-mystery show. A voice, whispering, “Hey, you, can you hear me? Do you ever think about murder?” was beamed toward customers as they browsed the mystery section in several independent bookstores in New York.