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ii The alveolar-retroflex contrast is a critical feature in Mandarin and is often used to differentiate Beijing Mandarin from other dialects of Mandarin like Taiwan Mandarin. While a number of linguistic and sociolinguistic factors have been found to affect the alveolar-retroflex contrast, leading to variation in Taiwan Mandarin, a consistent alveolar-retroflex distinction is described for Beijing Mandarin in the literature on Mandarin phonology. With a series of map tasks, this dissertation examines whether the production of alveolar-retroflex contrast in both dialects is subject to the effects of vowel context and focal prominence. With a discrimination task and a goodness rating task, the categorical and gradient modes of alveolar-retroflex perception in different vowel contexts are investigated for listeners of both dialects. Results of the production study indicate that the acoustic characterization of Beijing vs. Taiwan Mandarin alveolar-retroflex contrast varies by vowel and by how each contrasting phoneme is realized in a particular vowel context. Focal prominence is found to result in longer syllable durations but not increased spectral distinctiveness between the alveolar and retroflex sibilants. The findings ar