Assume that the displacement(s) of air is
proportional to the pressure difference (p)
created by a sound wave. Displacement (s)
further depends on the speed of sound (v),
density of air () and the frequency (f). If
p ~ 10 Pa, v ~ 300 m/s, ~ 1 kg/m³ and f ~ 1000 Hz,
then s will be of the order of (take the
multiplicative constant to be 1) :