A new invention has proven that audio can successfully be transmitted directly to a listener's ears without being audible to others around. Using ultrasonic waves beamed through a 3D-printed ...

When a plant is stressed, it doesn’t keep quiet about it. You won’t hear the plant’s cry because it’s in the ultrasonic range — too high-pitched for human ears — but, for decades, scientists have been ...

What do bats, dolphins, shrews, and whales have in common? Echolocation! Echolocation is the ability to use sound to navigate. Many animals, and even some humans, are able to use sounds in order to ...

Unlike traditional speakers, which emit sound waves in all directions, ultrasonic directional speakers use high-frequency ultrasound to create a narrow audio beam. This focused projection ...