Sound Energy causes mechanical vibration in any medium it passes through including air and the human eardrum.
Energy : J : = Force x Distance = Work, a quantity equivalent to the capacity of a physical system to do work; the SI unit of energy is the same as the unit of work - the Joule J and is a Scalar quantity.
1 J = 1 N·m = 1 kg·m2/s2 = 1 W·s = 107 ergs
Energy Flux Density : sometimes known as Intensity
Energy Spectral Density : ESD : describes how the energy of a signal or a time series is distributed with frequency.
Sound Energy : W : is the energy present in a sound field.
W = Wo · 10LW/10 J .... the units are Joules = Watt seconds
Total Sound Energy Density : sum of instantaneous potential and kinetic energy densities.
Sound Energy Flux : q : SI units : W/m2 = J s/m2
is the time average product of the in-phase components of the
Instantaneous Sound Pressure and the
Volume Velocity through the surface element considered. Also known as sound power through a surface element.
Sound Energy Flux Density : is the Sound Energy Flux in a specified direction and sense through an area perpendicular to that direction, divided by the area.