Timing patterns of tone and vowel in Mandarin: Evidence from f0-F1 turning point synchrony

We examine timing patterns of tone and vowel acoustics in Xi'an and Standard Mandarin. Using f0 and F1 difference trajectories between rising tone 2 and corresponding high-level tones in the diphthongs /ai/ and /au/ modelled with generalized additive mixed-effects models, we identify turning points as stable zero-crossings from velocity plots. Bayesian analyses showed that f0 and F1 turning points are not systematically different in time, indicating temporal alignment between tonal and vocalic acoustic landmarks. Turning points occur earlier in Xi'an Mandarin than in Standard Mandarin, and synchrony is more robust in /au/ than /ai/, revealing variety- and vowel-dependent timing patterns.