Investigation of the process underpinning vowel‐size correspondence

Vowel‐size correspondence is frequently reported in the literature: Namely, the vowels a and i tend to elicit bigger and smaller images, respectively. Previous studies have speculated that two factors may contribute to this vowel‐size correspondence: the acoustical features of vowels and the speaker's kinesthetic experience of producing them. However, these two factors have been investigated without being considered separately in previous research. In this study, we investigated the process underpinning vowel‐size correspondence by using speeded classification tasks and manipulating the two factors mentioned above separately in two experiments. The results of Experiment 1 indicate that a and i elicited bigger and smaller images even in the absence of kinesthetic experience. The results of Experiment 2 indicate that the proprioception of the size of the oral cavity on its own may not contribute to vowel‐size correspondence. Thus, the acoustic features of vowels mainly contribute to vowel‐size correspondence, although other possibilities are also discussed.