Revisiting the nature and the context of T4 alternations: insights from disyllabic, trisyllabic and quadrisyllabic word/digit productions in Taiwan Mandarin.

The tone values of a Tone 4 (T4) syllable are conventionally assumed to change from '51' to '53' when the syllable is followed by another T4 syllable in Mandarin Chinese. Literature focusing on T4 alternation is still inconclusive regarding the contexts for the alternations and whether the phenomenon should be better categorized as tone sandhi (i.e., represented as an abstract phonological rule in mental grammar) or tonal coarticulation (i.e., a natural articulation phenomenon at the phonetic level). The current study probes into these issues by focusing on disyllabic pseudowords, right-branching trisyllabic words as well as unstructured trisyllabic and quadrisyllabic digits. Productions from a total of 148 participants were collected and fundamental frequency (f0) contours, vowel lengths and f0 slopes were included in the analysis. The results from the experiments supported the tonal coarticulation view and showed that the trigger for the alternations was the high-onset tones following T4. Implications to the phonological analysis on tonal alternations in Mandarin Chinese are discussed.

A preliminary study on the online processing of anticipatory tonal coarticulation - Evidence from eye movements.

While the f0 realization of lexical tones vary extensively in contexts, little has been known on how listeners process the variation in lexical tones due to contextual effects such as tonal coarticulation in spoken word recognition. This study thus aims to fill the knowledge gap in tone perception with evidence from two types of anticipatory tonal coarticulation effects in Tianjin Mandarin, i.e., the slope raising effect due to a following low-falling tone and the overall-height raising effect due to a following low-dipping tone. An eye-tracking experiment with the Visual World Paradigm was carried out to compare participants' eye movements when they heard targets in three types of anticipatory raising conditions, i.e., the Slope Raising condition, the Overall-height Raising condition, as well as the No Raising condition (the baseline). The eye movement results showed significant differences in the proportion of looks to target between the Slope Raising condition versus the other two conditions, whereas the Overall-height Raising condition did not differ significantly from the No Raising condition. The findings thus suggest the facilitatory effect of tonal coarticulation cues in the anticipation of the upcoming tones, but listeners in this study seemed to be only sensitive to the raising in the f0 slope rather than the overall raising in the f0 height.