Abstract: By about 14 months of age, English infants show sensitivity to mispronunciations of consonants and vowels of familiar and newly learnt words when asked to identify a referent. They are also capable of learning two similar-sounding words. These findings suggest that infants possess phonologically detailed representations of words. However,very little is known about the role that tones play in early lexical representations. Word meaning is also distinguished by tones, which consist primarily of pitch level or contour variations in tonal language, like Chinese. While in English, a typically non-tonal language, pitch change only plays a role in the phrasal level as intonation. This study aims to answer the question: Do 16-month-old Chinese and English infants treat tones as phonological information in their lexical representations?
Using the intermodal preferential looking paradigm with the mispronunciation task, study 1 examined whether Chinese infants at 16 months were sensitive to mispronunciations of tones in monosyllabic, familiar words. 15 infants were separated into two groups. For group 1, the familiar words were pronounced correctly in block1, while mispronounced with the falling tone in Mandarin (T4) in block 2. The block order was reversed for the infants in group 2. Using a similar task to study 1, study 2 investigated whether English infants at 16 months were sensitive to tonal change in familiar English words when asked to identify a referent. In contrast with study 1, all the 12 infants received one kind of block order. In block 1, the words were pronounced with T4 as the familiar tone. A falling pitch contour is common in English and quite similar to T4 whereas it is less common to pronounce words with a fall-rise contour in English. Therefore, the dipping tone in Mandarin (T3) was used as the novel tone in block 2 and were considered as tone mispronunciations in study 2.
The results of study 1 showed that Chinese infants in group 1 looked longer at a target object when its label was correctly pronounced than when the label was mispronounced, in other words, a mispronunciation effect was found. In group 2, there were no systematic difference in infants’ preferences for the target between the pre- and the post-naming phase, neither when the target label was mispronounced or pronounced correctly. The results of study 2 showed that English infants looked longer at a target object when its label was pronounced with T4 than when the label was pronounced with T3. A positive correlation was found between English infants’ receptive vocabulary size and their performance in the mispronunciation condition.
In conclusion, the results indicate that 1) tones interact with phonological information for both Chinese and English infants at 16 months of age; 2) 16-month-old English infants may be on the way of learning to eliminate the phonological specificity of tone.

Key words: infant, tone, phonological specificity, mispronunciation effect