Imagine three people huddled in a circle so when one speaks, only one other hears. Scientists have created a device that works like that, ensuring sound waves ripple in one direction only. The device, ...

In context: Sound waves typically propagate in forward and backward directions. This natural movement is problematic in some situations where unwanted reflections cause interference or reduced ...

When underwater, humans cannot determine where a sound comes from. Sound travels about five times faster there than on land. That makes directional hearing, or sound localization, nearly impossible ...

Sound needs a medium (solid, liquid, or gas) to travel. Space is a vacuum, lacking the matter to carry sound waves. No sound in space means no echoes. While a near-perfect vacuum, some sounds can be ...

Chris Impey receives funding from the National Science Foundation. Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to ...