The system tracks a users hands movements using ultrasound . Gestures can skip through images , play videos and take selfies . It can also control characters in online games or control music . Ultrasound signals sent through the air from speakers in smartphones and tablets bounce against a user ’ s hand and are recorded by microphones . Elliptic Labs ’ uses these signals to recognise hand gestures . The company compared it to the way bats use echolocation to navigate .
The system tracks a users hands movements using ultrasound . Gestures can skip through images , play videos and take selfies . It can also control characters in online games or control music . Ultrasound signals sent through the air from speakers in smartphones and tablets bounce against a user ’ s hand and are recorded by microphones . Elliptic Labs uses these signals to recognise hand gestures . The company compared it to the way bats use echolocation to navigate .