The sound has always been 'immaterial' (well before the digital data), and it has always fascinated our perceptive apparati, because of its fleeting 'presence'. The sonic presence, in fact, organically is revealed through the eardrum vibrations and in the consequent electric signals sent to our brain. This is a common theme the sonic artists love to play with, till its essence, that is the remaining senses' perception of the sounds around us. Slowscan Soundwave (III) by Douglas Irving Repetto is an installation made with long semi-transparent polyester (mylar) strips that moves accordingly to the environment sounds, through a system made out of motors, strings and pulleys. These strips are illuminated by soft lights and so they generates shadows and reflections, moving unanimously, emulating a complex system moved by frequencies. The ethereal transparency and the strips' vibrations in waves materialize the abstract representation made by sinewaves in audio software. The atavic processes of the sounds' transmission through the air are reproduced with analogic mechanic tools, after being made public through the digital interfaces.