Those really are voices inside your head.

Bone conduction technology has existed for years now, resulting in more efficient hearing aids, high-tech active headphones, and gadgetry like Google Glass. These units work by passing sounds through a transducer that sits somewhere on a user’s skull. Unlike more traditional headphones, bone conduction technology makes most sounds inaudible to those besides the user.

In 2013 in Cannes, German broadcaster Sky Deustchland and advertising agency BBDO Germany premiered an advertising campaign at the International Festival of Creativity. The “Talking Window” campaign used bone conduction technology to transmit advertising content to public transit passengers who lean their heads against the window. Building on this concept, AT&T has filed patents for technology that can be used to target ads to users of mobile devices by learning their body language. “The device receives body language information associated with the body language of the user, analyzes the body language information to determine a physical activity being performed by the user, and selects an advertisement appropriate for the physical activity being performed by the user. The device can then provide the advertisement to the user,” AT&T says. Information can also be transmitted via the skin, another technology being investigated.

If you’re one of those people who mutes commercials and walks away from ads while they play before your videos, good luck escaping this marketing tactic!

Resources:
AT&T Developing Cool New Bone Conduction Technology for Mobile Devices(Atlanta Business Chronicle)
AT&T Refines Bone Conduction Technology for Gestures, Mobile Devices (Fierce Wireless)
Bone Conduction: Get Used to the Voices Inside Your Head (CNN)
Bone Conduction: The New Front in Guerilla Advertising (The Conversation)