This thesis attempts to identify and investigate the auditory impact distortion pedals impart on the source signal and consequently, how best to define, discuss and classify their individual, and collective, sonic signatures. This includes establishing a specialist lexicon with recontextualised descriptions for the specific adjectives of focus through means of both qualitative and quantative experimentation. This information is then visually represented by a ‘distortion wheel’ based in principle off the SCAA’s Coffee Tasting Wheel and how that allowed for the accessible retrieval of specialist terms within the contextual field. This is achieved through a series of etymological and audio-based analysis and experimentation. Qualitative experimentation was used to discover the initial descriptor list, critical sonic variables, and to subsequently define the words; quantative to match respective audio and signal analysis to the linked adjectives. The results showed ‘crunchy’ to be the most commonly used distortion descriptor. Through further analysis, it can be concluded that the Ibanez TS-9 is the crunchiest distortion pedal as its sonic features match closest to the defining traits of ‘crunchy’. Distortion pedals are subsequently successfully classified and descriptions for each adjective created to give the completed distortion lexicon.