Alongside its use for film, Peirce’s semiotics have also been used directly or adapted for other media and artistic analyses, such as music (Walsh 2001; Lomuto 2003; Kruse 2007), and particularly to acousmatic music (Atkinson 2007; Barreiro 2010; Bayle 2007). Many of these applications of Peircean semiotics are founded upon concepts from definitions in Peirce’s early account of his semiotic model (c. 1867-8). As a result there remains a strong and potentially confusing link between the concepts of similarity and iconicity which has proven problematic in describing and determining sonic iconicity. In musical semiotics much of the focus has been on the concept of musical iconicity, with the attendant criticisms that iconicity, and therefore similarity, is sufficient to describe the way that music functions as a sign (Howard 1971: 272-273).
More recently, Peircean terminology has been applied to sound in areas such as sonification, auditory display and product sound design (Suied et al. 2005; Blauert and Jekosch 2003; Blauert and Jekosch 2005). In some texts on auditory display, the terminology is similar to Peirce’s, but the meaning is more closely related to an equivalent of the visual icon in a desktop interface (Hermann, Hunt and Neuhoff 2011). In true applications of Peirce’s semiotics the delineation between iconic, indexical, and symbolic has proven to be elusive. In their discussion of the triadic sign, Suied et al. give examples of icons, indices, and symbols. The example of an icon appears to conflate the representative function of icon and index: “The sound of ruffled paper is an iconic sign if it means that a document is thrown in the basket on a computer interface. The relationship between the sound and the object is obvious; it is just a synthesised real-life sound” (Suied et al. 2005: 4). Since it is similar, the argument runs, it is therefore iconic. The example of an indexical sound is also potentially ambiguous: “A sound with a progressively increasing pitch indicating the sending of an email is an indexical sign; there is a direct link between the sound and the object it represents, the evolution in time” (Suied et al. 2005: 4) . Although synchronised with the action, it could also be argued that there is no actual evidentiary link between an email being sent and a rising pitch. The sound has merely been selected to represent that action. Eventually, of course, the aim is that it will be understood as an indexical sound, once the convention has been learned to the extent that the convention itself has become naturalised, just as a telephone ringtone is initially symbolic, then, once learned, acts as an indexical sign.
The Peircean iconic definition that will be used here is not one which is typically used by either sound or musical semioticians or those interested in visual-centric analyses which frequently adopt the definition of the icon from Peirce’s early account which focuses on the idea of similarity or resemblance. This early definition from his article "On the Algebra of Logic" [1885] is typical: “I call a sign which stands for something merely because it resembles it, an icon. Icons are so completely substituted for their objects as hardly to be distinguished from them” (Peirce, Fisch, Moore, Klousel 1982: 5.163). Yet by 1903 Peirce used an alternative definition of the icon which rested less on similarity than on characteristics or properties: “An icon is a representamen which fulfils the function of a representamen by virtue of a character which it possesses in itself, and would possess just the same though its object did not exist” (Peirce, Hartshorne and Weiss 1960: 5.73) and this from 1904: “An icon is a sign fit to be used as such because it possesses the quality signified” (Peirce Edition Project 1998: 2.307).
This is an important distinction, as many of the discussions and criticism of iconicity rest on the assumption that an iconic relationship requires similarity. As an example of the Peircean category of Firstness, adopting a definition of the icon being "related by similarity" necessarily asks the question: similar to what? Similarity necessitates a second with which to be compared. An icon (belonging to the category of Firstness), however, need not be similar since it has characteristics it possesses regardless of any other. By using Peirce’s later, clearer definition of the icon, relating to its properties and characteristics rather than its similarity to something else, we simultaneously and subtly reframe both the index and symbol. The index then becomes differentiated from an icon more clearly as a sign which is linked to some other and falls clearly in the category Secondness, either by existential relation or reference (Peirce Edition Project 1998: 2.274). Symbols, in the category Thirdness, function as signs “merely or mainly by the fact that [they are] used and understood as such, whether the habit is natural or conventional, and without regard to the motives which originally governed its selection" (Peirce, Hartshorne and Weiss 1960: 2.307).
Along with the clarification in definitions in his first major revision of his semiotic system, Peirce also revisited the division in both the immediate and dynamical object and interpretant:
we have to distinguish the Immediate Object, which is the Object as the Sign itself represents it, and whose being is thus dependent upon the Representation of it in the Sign, from the Dynamical Object, which is the Reality which by some means contrives to determine the Sign to its Representation. In regard to the Interpretant we have equally to distinguish, in the first place, the Immediate Interpretant, which is the interpretant as it is revealed in the right under- standing of the Sign itself, and is ordinarily called the meaning of the sign; while in the second place, we have to take note of the Dynamical Interpretant which is the actual effect which the Sign as a Sign really determines. (Peirce, Hartshorne and Weiss 1960: 4.536)
By adopting these definitions from Peirce’s later account in application to the practical usage of sound, sonic material may genuinely be described in iconic terms of its properties and characteristics, regardless of its links to anything else. Similarly, we can describe it in terms of its synchronisation with an image, which now firmly produces an indexical link, whether real or through design. We may also describe it in terms of a symbolic sign, where the sound has come to symbolise something through habit or convention. In practical terms it may simply mean linking a sound with an image, character, or situation a sufficient number of times until one eventually serves to represent the other.
The Peirce model can also be applied self-reflexively to analyse creative decisions in the sound design process. A number of case study films will be used to illustrate the potential for the model to explicate areas of sound practice and sound analysis which were previously too cumbersome or too difficult to analyse using other approaches. This approach is then used to illustrate different aspects of sound design practice, such as the underpinning rationale for a particular sound design approach, the choice for an individual sound design, the effect of a particular sound and image combination, or the introduction and reuse of sound signs to create narrative links. The strengths of this model are numerous – it can be applied retrospectively to analyse sound and sound/image combinations and can also be used as a guide to sound design choices. It applies to both macro and micro level, from a whole soundtrack/narrative perspective to individual sound choices. Finally, it provides a metalanguage of sound and thus allows sound practitioners and non-specialists to discuss sound though its function, effect, and meaning.