Using extremely high, low and very quiet sounds to affect listeners

The human ear can only detect a certain range of frequencies. This is the range that all of our music is composed in. But the use of notes that lie above and below the range of human hearing can have a subtle impact on the listener. Even though we cannot hear the sounds, our bodies can nonetheless detect them.
How can this be used?
We can use these outer frequencies to create sub-layers of harmony and dissonance within compositions. A mega-low bass note can reinforce a strong chord within a progression and conversely, a low or high not that does not agree with a chord can create greater subtle tension and unease through a section.

Similarly; there is an endless amount of subtle variation that can be achieved through the use of multiple layers of sound mixed to points of variable inaudibility in songs. These elements could be melodic, rhythmic or non-musical and through careful combination can enhance the flow and feel of recorded music.