<P> The energy carried by an oscillating sound wave converts back and forth between the potential energy of the extra compression (in case of longitudinal waves) or lateral displacement strain (in case of transverse waves) of the matter, and the kinetic energy of the displacement velocity of particles of the medium . </P> <P> Although there are many complexities relating to the transmission of sounds, at the point of reception (i.e. the ears), sound is readily dividable into two simple elements: pressure and time . These fundamental elements form the basis of all sound waves . They can be used to describe, in absolute terms, every sound we hear . </P> <P> However, in order to understand the sound more fully, a complex wave such as this is usually separated into its component parts, which are a combination of various sound wave frequencies (and noise). </P> <P> Sound waves are often simplified to a description in terms of sinusoidal plane waves, which are characterized by these generic properties: </P>

How many sources of sound do we have