A longitudinal wave A transverse wave Not a wave at all A form of nuclear power
Air Water Metal A vacuum
How near it is How far away it is Its amplitude Its frequency
A bounce A ping An echo A pong
Very loud machinery A quiet field A smelly CD player A smoky fire
Very loud sound Very quiet sound Sound with a wavelength of more than one Volt Sound with a frequency of more than 20,000 Hertz
Cleaning delicate items Range and direction finding Pre-natal scanning Telecommunications broadcasting