Rime changes and mergers in Beijing retroflex suffixation: an acoustic study

Beijing Mandarin allows all possible rimes (excluding syllabic [ɚ]) to be applied with the retroflex suffix, and reveals an intricate pattern of rime change and merger. While retroflex suffixation and resultant rime mergers have been approached from phonological and impressionistic phonetic angles, empirical studies remain scarce and inconclusive. This investigation is a step towards filling that gap. 10 Beijing Mandarin speakers were recorded. MANOVAs were performed for the effects of suffixation and rime identity on F1 and F2 frequencies of nuclear vowels: Pillai’s trace (PT) was used as a metric of overall spectral difference. Symmetric differences between the probability density functions (PDF) of each formant frequency in suffixed vs unsuffixed rimes were computed. Results are reported for rimes that were previously claimed to merge: those with high, mid-unrounded, and low nuclei. With an overall shrinkage of the vowel space, suffixed nuclei are globally retracted, while high vowels also tend to be lowered and low vowels to be raised. Our findings confirm complete acoustic neutralisation of the nuclear [a] rimes, where monophthongal rimes merge with those ending in [i] and [n]. On the other hand, suffixed [ie, y, u, ei] remain acoustically distinct within their merger groups. These statistically significant acoustic differences are small and likely to be imperceptible, pointing to potential incomplete neutralisation.