The efficiency of this algorithm depends on two contrasting factors.

In contrast Factor 2 and Impulsive antisociality of the PPI-R are associated more strongly with criminality.

The acoustic contrast factor is a number used to describe the relationship between the densities and the sound velocities (or, equivalently because of the form of the expression, the densities and compressibilities) of two media.

In the latter context, the acoustic contrast factor is the number which, depending on its sign, tells whether a given type of particle in a given medium will be attracted to the pressure nodes or anti-nodes.