While examples have been clearly attested in the literature, the reversal of a merger is an uncommon occurrence that apparently contradicts principles underlying sound change. Understanding the implications of merger reversal therefore requires understanding of their implementation: whether there was a full merger in the first place, what the phonetic path taken to separate the merger was, and whether there was a social motivation behind the reversal. I take this approach in a case study of the traditional start-north merger of St. Louis English, which has reversed in recent decades. I show that the merger was most likely a near merger, that the reversal was achieved by raising north and fronting start, and that the reversal, at least the raising of north, was socially motivated. I argue that the data highlights the role of perceptual salience in reversing mergers and illustrates that merger reversal can at times be chain shift-like in appearance, if not execution.

虽然文献中已经清楚地证明了一些例子，但合并的逆转是一种罕见的事件，显然与健全变革的基本原则相矛盾。因此，理解合并逆转的含义需要了解它们的实施：首先是否存在完全合并，分离合并所采取的语音路径是什么，以及逆转背后是否存在社会动机。我在一个案例研究中采用了这种方法，该案例研究了圣路易斯英语的传统开始-北方合并，近几十年来这种情况发生了逆转。我表明合并很可能是接近合并，逆转是通过向北和向前开始来实现的，而且这种逆转，至少是北方的崛起，是出于社会动机。我认为，这些数据突出了感知显着性在逆转并购中的作用，并说明并购逆转有时在外观上可能类似于链式转移，如果不是执行的话。