Voicing Constraint and Segmental-Tonal Neighborhood Effects on Clusters in Thai

Investigating existing and non-occurring onset clusters in Thai led to the postulation of a voicing constraint. Native speakers were asked to give well-formedness judgments to novel words with and without violations of the constraint. The findings support the argument for the existence of the constraint in the speaker's mind. Furthermore, it was found that within all groups of novel words, categorized by whether or not they obey the constraint and whether or not they contain the existing clusters, there were segmental neighborhood effects. The novel words in dense segmental neighborhoods were rated significantly higher than those in sparse segmental neighborhoods. Finally, the present study puts forward the proposal and evidence that the degree of tonal neighborhood density also influences the speaker's perception of novel words. 1. Clusters in Thai Putting true Thai words in minimal pairs reveals that the language has 11 possible consonant clusters, which show up exclusively in the onset position (Naksakul 1998). The clusters consist of /pr p hr pl phl tr kr khr kl kh1 kw / and /khw/. That is, the second consonant of a legal cluster is restricted to those in the set {r, 1, w}. Regarding the first consonant, they are drawn from the set of consonants belonging to the plosive class shown in (1)