Sound word puzzle Crossword

What is the beginning how a sound is produced?
Sound with a frequency higher than 20,000 Hertz
The location of objects by reflected sound, especially used by dolphins and bats.
Humans use ultrasound to produce images of structures inside the human body.
What made the speed of light and sound different?
Traveling faster than the speed of sound.
Something a plane that travels faster than the speed of sound breaks through.
A visible cloud of condensed water that forms around the plane.
The frequency of sound can change for observers if the object is moving.
What is the science of sound called?
A navigational technique used by ships and submarines.
An empty space.
Moving back and forth at a regular speed
A wave moving in parallel direction.
The lowest point of a wave.
The reciprocal of Frequency.
The rest position.
One complete path of a wave
When a wave encounters a barrier, it can bounce off the surface of it.
The interaction of waves.
The resultant wave has an amplitude higher than the individual ones