Composer Kaija Saariaho was well known for her diverse catalog of electroacoustic compositions. In her works, she created musical tension by using a methodology called sound/noise axis, in which she thought of timbral change as a superior developmental parameter to those such as harmonic function. In this presentation, I will discuss the role of timbral transformation through my analysis of Saariaho's NoaNoa, reference her sound/noise axis methodology, and incorporate and build upon elements from Michael Clarke's interactive aural analysis approach. I argue that timbral transformation is the leading developmental parameter used in electroacoustic music, indicated by the capabilities of electronic synthesis and works within the repertoire.