2.3 Looking at looking at sound
This chapter has identified ways in which sound may manifest visual patterns on the surface of a physical system. In Chladni/Jenny type Cymatics the acoustic interactions of physical matter give rise to formations and shapes that favour resonance within the system. To the human eye the manifestation of these shapes is perceived as an instantaneous reaction to the sound that is happening 'now'; oscillations within this type of system are of frequencies that are perceived as sound and so the eye may only perceive the patterns resultant of their periodicity. In the harmonograph sub-sonic oscillations are traced over relatively long periods of time to reveal, at a rate comprehensible to the eye, the shapes of what are, in principle, acoustic interactions.
Harmonograms and Cymatic patterns can bring only specific harmonic content to the visual domain, providing representations of the motion that has occurred within a two- or three-dimensional space. Although manifest over time, the passage of time is not itself represented in these cases. In the phonautograph and related systems the passage of time is represented as one of the visual dimensions allowing representations of arbitrary sound to be written.
Some psychological aspects of perception have also been introduced. Concepts pertaining both to psychoacoustic and visual perception – as well as to the physical phenomena discussed above – are engaged by this project as inspiration in the creation of, and composition with, computer music software systems.