Perceptual Representation of Consonant Sounds in Thai

This work is an attempt to construct a perceptual representation of Thai consonants based on perceptual identification results (from 28 Thais) of 21 phonemes presented in noise. The experiment is designed to equally make pairwise comparisons among 21 word-initial phonemes, which results in 210 real-word stimulus pairs. Percent correct responses and confusion matrices are obtained. Similarity score and perceptual distance for each phoneme pair are systematically derived from confusion scores based on a method proposed by Shepard (Psychological Representation of Speech Sounds, 1972). Piecing this together pair by pair, a perceptual space or representation of Thai consonants takes shape. The perceptual space could roughly be divided into 5 non-overlapping groupings: glide, glottal constriction, nasality, aspirated obstruent, and a combination of liquid and unaspirated obstruent. It is suggested that these phonological classes reflect the most distinct and relevant perceptual properties of Thai consonants. Preliminary cross-linguistic observation is addressed in light of the data of English consonants from Miller and Nicely (J. Acoust. Soc. Am., 1955).