Low boundary tone: Evidence from the acoustic differences between Cantonese sentence-final particles with low-falling tone

This study investigated the nature of the tones on Cantonese sentence-final particles (SFPs) with low-falling tone. Four Cantonese SFPs with different intonations were examined: aa4 , le4 , lei4 , and zaa4 . Ten native adult speakers of Cantonese participated in production experiments. Smoothing Spline ANOVA results suggested that, despite the same citation tone (tone 4, low-falling tone), the F0 of aa4 , le4 , and zaa4 was significantly lower than that of lei4 when they functioned as expressing intonation at the utterance-final position. However, there were no significant differences between the F0 of all four SFPs and their (near-)homophones when they were produced as lexical items in the middle of a sentence. The F0 differences found between the SFPs at the utterance-final position can be attributed to the superimposition of low boundary tone on aa4 , le4 , and zaa4 . My results supported the hypothesis that the low-falling tone on aa4 , le4 , and zaa4 is a combination of lexical tone (tone 4) and intonation (low boundary tone), and that on lei4 is merely tonal.