Infants’ Sensitivity to Lexical Tone and Word Stress in Their First Year: A Thai and English Cross-Language Study

ABSTRACT

Non-tone language infants’ native language recognition is based first on supra-segmental then segmental cues, but this trajectory is unknown for tone-language infants. This study investigated non-tone (English) and tone (Thai) language 6- to 10-month-old infants’ preference for English vs. Thai one-syllable words (containing segmental and tone cues) and two-syllable words (additionally containing stress cues). A preference for their native one-syllable words was observed in each of the two groups of infants, but this was not the case for two-syllable words where Thai-learning infants showed no native-language preference. These findings indicate that as early as six months of age, infants acquiring tone- and non-tone languages identify their native language by relying solely on lexical tone cues, but tone language infants no longer show successful identification of their native language when two pitch-based cues co-occur in the signal.

Acknowledgments

The first author’s work was supported by the European Union’s Horizon 2020 Marie Sklodowska-Curie individual Fellowships European Programme under Grant Agreement No 798908 Optimising IDS, and she receives support from the Basque Government through the BERC 2018–2021 program, and from the Spanish Ministry of Science and Innovation through the Ramon y Cajal Research Fellowship, PID2019–105528GA-I00. We would like to thank Dr Benjawan Kasisopa for her assistance with stimulus selection and experimental set up and Mr Johnson Chen for creating the experimental software. We also thank Ms Hana Zjakic and Ms Nawasri Chonmahatrakul for their assistance with data collection. We are grateful to all the infants and their parents for their valuable time and interest in this research.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Ikerbasque, Basque Foundation for Science [BERC 2018-2021]; Marie Sklodowska-Curie [No 798908 Optimising IDS]; Spanish Ministry of Science and Innovation [PID2019-105528GA-I00].