The University of Washington research team behind the technology, known as CovertBand, tested it using a 42-inch Sharp TV in five different Seattle homes.They found that the method is able to track the physical movements of multiple people to within 18 centimeters of accuracy, and even differentiate between particular gestures and motions. The tech can also track people, though less accurately, through walls.
They also demonstrated that listeners couldn’t distinguish between songs containing the hidden sonar signals, and those without it. ...and all CovertBand needs to work is a speaker and a microphone. more
