Audio enclaves are made using ultrasound waves, which are higher frequency than the sound waves we can hear. Two waves are ...

A team of researchers have developed "audible enclave" technology that creates pockets of sound that can be heard at a ...

By combining ultrasound with a concept called nonlinear acoustics, you can create sound that stays silent until it reaches a ...

Sound waves can reflect off surfaces ... The speed of sound in air can measured using two wooden blocks, a tape measure or trundle wheel and a stopwatch: two people (person A and person B ...

As an airplane flies faster than the speed of sound, it "pushes" on the sound waves in front of it. But sound waves obey the speed limit—they can't travel faster than the speed of sound.

You may have used a method known as the clap-echo method in the playground or you may have used a computer-timed method with two sound-activated switches. Using the apparatus shown above and with ...