When you blow air past these harp strings, they produce sounds.
An artificial echo device.
A 30 metre tube which demonstrates that echoes are reflections of sound
Message through the water
Messages are sent through a tank of water as sonar pulses
Sound is made visible with gas flames.
By moving a sonar transponder in a tank the outline of a model submarine can be seen on a computer screen
Two loudspeakers are driven by sine-wave oscillators. Combining slightly different frequencies gives corresponding 'beats' in time.
Wait and Hear
Shows how hearing your own speech delayed by about half a second can make it difficult to carry on speaking.
Reflection and focusing of sound using large parabolic reflectors.