Asymmetries in the perception of sub-categorical variation

Abstract

Both VOT and vowel nasality show low-level variation in English that may be perceptually motivated (and which, in any case, has perceptual consequences). This study examines the perceptual salience of such variation, investigating in particular a possible perceptual asymmetry between increased vs. decreased degrees of these phonologically relevant features. On each trial of an AXB perceptual task, listeners heard three repetitions of the same word: a token with unchanged phonetic feature (X) and tokens with phonetic features that were artificially increased and decreased to the same degree (A and B). Listeners then had to determine which of the two flanking items (A or B) sounded more similar to the middle item (X). Test words included 18 monosyllabic words with initial /p/ (in simple onsets) and 19 monosyllabic words with nasal codas and were heard by 40 listeners. Based on preliminary work, participants are expected to judge decreased-feature stimuli of both types (VOT and nasality) as more similar to the natural stimuli, suggesting that increasing these phonetic features is perceptually more salient than decreasing them. These findings demonstrate asymmetrical sub-categorical sensitivity for features known to be perceived categorically (VOT), as well as for features not primary to phonological contrast (vowel nasality).