Re-Thinking the Place of Semiotics in Psychology... 123user or person, resulting in ambiguity in the conception of the pivotal notion of signal-referent
relation strength, and leading, in turn, to a research strategy that is fatally flawed.
In the Peircean tripartite division of signs (Peirce, 1932, 2.228-307), the distinction
between the three types is based on the dyadic relation between signifier and signified. An
icon resembles the signified, either in terms of similar intrinsic properties, or in terms of
similar functions (Peirce's earlier term for "icon" was "likeness")(e.g., a diagram, a picture,
the ideographs found in Egyptian hieroglyphics). An index (or indicator) is causally related to
(either as cause or as effect of) the signified (e.g., clouds may indicate impending rain, a
bird's warning cry may indicate the presence of a predator). A symbol, as implied by the
original meaning of the term (i.e., "something thrown together") has no natural connection
with the signified^16 (e.g., the word "table", either graphically or acoustically, has no natural
connection with the object).
Here, semiotics allows us to clarify that so-called auditory icons (unlike typical visual
icons) are misclassified. Consistent with Peirce‘s usage, the word icon (derived from the
Greek eikon, meaning ―likeness‖ or ―image‖, such as a picture or a statue) has straightforward
application in the visual domain. However, when the concept of an icon is applied in the
auditory domain, the situation becomes much less straightforward (which helps to explain
why research developments and successes in the auditory domain have lagged behind those in
the visual domain). Strictly speaking, an auditory icon would be a sound used to stand for
another sound by virtue of acoustic similarity (e.g., a mouse's squeak used to stand for a
baby's cry). But this is not what is meant in the auditory warning literature at large. Instead,
the term icon is used generally for what Peirce referred to as index. Furthermore, in the
natural environment, an index can indicate any number of things associated with that sound
(its source, the physical properties of that source, its causal antecedent, its effect, its context,
etc.). Now, with respect to the indexical function of signals, these may be natural or
conventional. Hence, we can clarify that auditory icons are not icons at all. Instead, the term
auditory icon actually denotes a natural indicator (index) adopted or adapted for the purpose
of conventional indication. Auditory icons thus belong to the mixed semiotic phenomena
category (7) in our earlier classification of meanings. And how easily they are learned or
recalled will depend very much on another factor, the already-learned associations of the
person who is to learn them. That is, the third term of the signifying relation cannot be
ignored. This leads directly into the second problem.
In the Peircean classification of signs, any particular sign may be taken to be an icon,
index or symbol. The same sound (e.g., a mouse‘s squeak) may be an icon (for a baby‘s cry),
an index (for the mouse) or a symbol (for an earthquake). But none of the binary relations
constitutes a sign without the third term, the person or cognising subject. Consistent with the
semiotic triad, indication is always an indication to the person or cognising organism - the
third term of the semiotic relation. The theory of signification emphasises the need to
consider not just the dyadic relation between signal and referent, but the full triadic relation
between signal, referent, and person. But the person is not an empty cogniser; the person is a
cognisor with a prior history of learned associations.
(^16) In non-Peircean classification, symbols may be conventional or nonconventional. In the latter case, symbols are
typically substitutes for the symbolised, and, there, the basis of the substitution typically lies in iconicity - in
similarity (of form or function). This point is taken up in the next section.