Sound waves can reflect off surfaces. We hear reflected sound waves as echoes. Hard, smooth surfaces are particularly good at reflecting sound. This is why empty rooms produce lots of echoes.

Scientists from ETH Zürich developed a circulator device that uses self-sustaining oscillations to propagate sound waves in ...

Your starting point is the speaker triangle: an equilateral setup with speakers angled toward the listener. Position yourself ...

When someone speaks, sound waves hit the eardrums ... "helping us reduce unwanted reflections and increase signal clarity." ...