Acoustic versus articulatory accounts of asymmetries in vowel perception

Abstract

Most research on cross-language speech perception has concentrated on how and when the discrimination and categorization of speech sounds change with specific linguistic experience. It has become increasingly clear, however, that there are also universal biases in place early in development that guide and constrain how perceivers from diverse linguistic backgrounds decode the speech signal. In the domain of vowel perception, it is now known that perceivers (both adult and infant) are universally biased toward articulatorily and acoustically extreme vowels. This generic vowel bias is often demonstrated in discrimination tasks as a directional asymmetry: perceivers perform better when discriminating changes from less to more peripheral vowels compared to the reverse. I will discuss evidence indicating that the processes underlying these asymmetries operate on articulatory information, rather than on acoustic information per se. I will begin with findings from cross-language experiments with adults indicating that asymmetries occur with vowels presented in either the auditory or the visual modality, regardless of native language. I will then present findings indicating that analogous asymmetries in visual perception emerge using schematic non-speech visual analogs of vowels, but only if the optical stimuli depict both lip-motion and configural information, consistent with an articulatory account of asymmetries.Most research on cross-language speech perception has concentrated on how and when the discrimination and categorization of speech sounds change with specific linguistic experience. It has become increasingly clear, however, that there are also universal biases in place early in development that guide and constrain how perceivers from diverse linguistic backgrounds decode the speech signal. In the domain of vowel perception, it is now known that perceivers (both adult and infant) are universally biased toward articulatorily and acoustically extreme vowels. This generic vowel bias is often demonstrated in discrimination tasks as a directional asymmetry: perceivers perform better when discriminating changes from less to more peripheral vowels compared to the reverse. I will discuss evidence indicating that the processes underlying these asymmetries operate on articulatory information, rather than on acoustic information per se. I will begin with findings from cross-language experiments with adults indicatin...