Sound to meaning correspondences in spoken language are assumed to be largely arbitrary. However, research has identified a number of exceptions to the arbitrariness assumption. In particular, non-arbitrary mappings between sound and shape, the bouba/kiki effect, have been documented across diverse languages and both children and adults are sensitive to this type of sound symbolic mapping. The cognitive basis for the associations between nonword labels and particular shapes remains poorly understood making it difficult to predict how findings generalize beyond the limited stimuli tested. To identify systematic bases for sound-to-shape mappings, we collected ratings of roundedness and pointedness for a large database of pseudowords. We find that attributes of both consonants and vowels are systematically related to judged shape meanings of pseudowords, and offer hypotheses as to the cognitive mechanisms underlying the observed patterns

Although the relationship between sound and meaning in language is arbitrary, reliable correspondences between sound and meaning have been found in natural language. These sound symbolic relationships affect word learning, but less is known about how sound symbolism affects online processing during learning or for well-learned stimuli. We use the visual world paradigm and an artificial lexicon featuring carefully controlled sound symbolic correspondences to examine the effects of sound symbolism on the online processing of novel and well-learned stimuli. Initially, participants chose novel shapes matching the sound symbolic properties of the word above chance, reliably fixating consistent shapes around word offset. As learning approached ceiling, accuracy and reaction time differences between matching and mismatching stimuli disappeared but a disadvantage in the online processing of mismatching stimuli persisted in the form of lagging target fixations. This suggests that sound symbolism affects the online processing of spoken stimuli even for well-learned words.