Tones of Beijing dialect since 1900 and their evolution

Since the discovery of real-time tone evolution in Thai and Chinese dialects, the existence of circular tone shift has been largely confirmed. The clockwise shift (high > rising > low > falling > high) has been found to be more prevalent than the counterclockwise shift (high > falling > low > rising > high). This study extracted tone patterns from five early recordings of citation tones in Beijing dialect dating from 1900 to the 1930s, and performed a quantitative acoustic analysis of tone evolution of Beijing dialect by comparing tonal differences between early recordings, early experimental results, and modern data. A clockwise tone shift in Beijing dialect since 1900 is confirmed: T1, high convex falling > high level; T2, high convex rising > mid concave rising; T3, low rising > low falling-rising, with intensified creakiness; and T4, lower falling > higher falling. By integrating these results with earlier documentation, this study uncovers a nearly completed circle of the fast-paced tone shift: the tone value of each tone has almost shifted to the value of its downstream tone in the clockwise direction over approximately 200 years. Two possible motivations for tone evolution in Beijing dialect are identified: truncation-like effects coupled with hypocorrection, and push/drag effects between neighboring tones. These findings provide concrete evidence for clockwise tone shift and contribute to a better understanding of tone evolution.