Simple and complex crossmodal correspondences involving audition

The last few years have seen an explosion of interest from researchers in the crossmodal correspondences, defined as the surprising connections that the majority of people share between seemingly-unrelated stimuli presented in different sensory modalities. Intriguingly, many of the crossmodal correspondences that have been documented/studied to date have involved audition as one of the corresponding modalities. In fact, auditory pitch may well be the single most commonly studied dimension in correspondences research thus far. That said, relatively separate literatures have focused on the crossmodal correspondences involving simple versus more complex auditory stimuli. In this review, I summarize the evidence in this area and consider the relative explanatory power of the various different accounts (statistical, structural, semantic, and emotional) that have been put forward to explain the correspondences. The suggestion is made that the relative contributions of the different accounts likely differs in the case of correspondences involving simple versus more complex stimuli (i.e., pure tones vs. short musical excerpts). Furthermore, the consequences of presenting corresponding versus non-corresponding stimuli likely also differ in the two cases. In particular, while crossmodal correspondences may facilitate binding (i.e., multisensory integration) in the case of simple stimuli, the combination of more complex stimuli (such as, for example, musical excerpts and paintings) may instead be processed more fluently when the component stimuli correspond. Finally, attention is drawn to the fact that the existence of a crossmodal correspondence does not in-and-of-itself necessarily imply that a crossmodal influence of one modality on the perception of stimuli in the other will also be observed