In language change, a reversal of a merger is generally considered to be impossible, since after two sounds have become fully merged, they are no longer distinct, so no phonetic or phonological cues exist that could reverse this process. This article investigates such an 'impossible' merger reversal: the split of the Bären vowel (orthographically represented by <ä> or <äh>) and the Beeren vowel (orthographically represented by , or in Austrian Standard German. We investigated a corpus of spoken data, measured the acoustic properties of the vowels, and determined the degree of the merger (by computing Pillai scores) for younger and older speakers. It turns out that the two sounds were formerly merged, but currently a split can be observed as an ongoing process. This paper argues that language contact with Standard German as it is spoken in Germany motivates the ongoing reversal. Since the Bären vowel is also subject to substantial variation in German Standard German, in order to get the split right, Austrian speakers are likely to invoke orthographical knowledge. We will consider the mental representations of this sound, including the graphemic representations from an Exemplar-theoretical viewpoint.
Reversal of a MergerIn a merger, two different sounds converge on a single sound. It is usually assumed that a merger, if completed, cannot be reversed for the logical reason that after merging no phonetic or phonological cues exist that can serve as a means for reversal. Even in dialect contact, in which dialect M has the merger and dialect S has the split, M speakers will not learn the split, for they are not able to perceive the categorical distinction; if speakers try to reverse a merger, they will not get it