Reading in Thai: the case of misaligned vowels

Thai has its own distinctive alphabetic script with syllabic characteristics as it has implicit vowels for some consonants. Consonants are written in a linearorder, but vowels can be written non-linearly above, below or to either side of theconsonant. Of particular interest to the current study are that vowels can precede theconsonant in writing but follow it in speech, hence a mismatch between the spokenand written sequence occurs, for example ‘flat’ is spoken as /bɛ:n/ or in amore severely misaligned example where the vowel operates across syllables theword ‘insect’ is spoken as /m(a)lɛ:ŋ/. In order to investigate if there is aprocessing cost associated with this discrepancy between spoken and writtensequence for vowels and the implications this has in relation to the grain size usedwhen reading Thai, eye movements of adults reading words with and withoutmisaligned vowels in sentences using the EyeLink II tracking system was conducted. Twenty-four university students read 50 pairs of words with misaligned andaligned vowel words matched for length and frequency embedded in same sentenceframes. In addition, rapid naming data from forty adults was collected. Data fromforty children 6;6–8;6 years old reading and spelling comparable words was alsocollected and analysed for errors. Results revealed a processing cost due to the moreseverely misaligned words where the vowel operates across the syllable, and givessupport for a syllabic level of segmentation rather than phonemic for reading andspelling in Thai adults and children.