Is segmental foreign accent perceived categorically?

Abstract

The second language learning process involves acquisition of sounds that differ to varying degrees from the sounds of a learner’s native language. Learners’ productions are strongly influenced by their native language particularly for sounds which are similar but non-identical in the two languages. However, foreign accent is typically investigated at the level of utterances and as a consequence the segmental basis of foreign accent and its role in communication remain unclear. The principal issues addressed by the current study are whether accentedness at the segmental level is judged categorically by native listeners, and whether consonantal and vocalic segments are treated similarly. British English listeners judged as native or non-native a series of words in which a single vowel or consonant had been replaced by its Spanish-accented counterpart. The degree of segment accent was varied in equal amounts along a 21-step continuum using a blending technique based on native and non-native segments excised from words spoken by a balanced bilingual talker. Listeners assessed 24 distinct consonant and vowel continua. Averaged across all vowel or consonant continua, listeners’ nativeness judgements varied with segment nativeness in a non-categorical fashion. However, most individual consonant continua, as well as those vowel continua that involved durational changes, were perceived categorically. These results suggest that while overall segment-level foreign accent might be considered to vary in degree, in reality at the level of individual segments –where second language learners’ pronunciation awareness and control has to be focussed– small acoustic changes can convey a foreign accent.