Taro or Oyster? the production merger of the two mid back vowels, [o] and [], in a major dialect of Taiwan Southern Min

One of the two major dialects of Taiwaesen Southern Min [TSM] has two mid back vowels,/o/and//. This distinction is well documented in classic Chinese phonology and agreed upon by most TSM linguists. However, an increasing number of recent evidence-based studies have reported the falling together of these two vowels and, indeed, many non-linguists as well have noticed the loss of the distinction. Since these two vowels are so similar in nearly all phonetic features most studies carried out heretofore which concluded that the merger had in fact taken place were based on auditory criteria. The present study, however, the methodology of which has been designed to take account of the low literacy rate of TSM speakers, as well as the frequent contact which takes place between TSM dialects, investigates the status of these two vowels making use of both acoustic and statistical data. Results indicate that in TSM/o/and//have merged in the case of younger speakers. Both internal and external factors are proposed which have affected the merger, and the further suggestion is put forward that, though the instance of sound shift reversal in Taiwan is on record, this is not likely to occur in the case of TSM/o/and//.