On the phonemicization of the Old High German i -umlauts

: In this article it will be argued that the Old High German i -umlaut phenomena produced phonemic changes before the factors that triggered them off changed or disappeared. When they reached their final stages, the products of i -umlaut became distinctive in the phonological system of the language and contrastive at a lexical level.

1.The Old High German distance assimilation changes generally known as i-umlauts affected a great number of vowels, both short and long, as well as the inherited diphthongs.
Since i-umlaut is caused by i-sounds in the following syllable (/i/, /i:/, /j/), the relevant changes must have taken place before the factors that triggered them off changed or disappeared.This means that i-umlaut was completed before or during the Old High German period (ca.750-1050), even if it is not normally indicated in the available sources, except for the mutation of /a/ (written e) 1 .The gap between the time when the relevant changes occurred and the time when the Middle High German available sources begin to indicate (tentatively and inconsistently) the umlauted vowels has generally been regarded as a difficulty in the reconstruction of the phonological processes involved.
In a well-known article published in 1938, William F. Twaddell tried to resolve this difficulty by maintaining that there was no reason for the scribes to indicate the Old

On the phonemicization of the Old High German i-umlauts
High German umlauted vowels, since these were merely allophones of the original phonemes.But when the triggering factors changed or disappeared, these allophones became phonemes and the scribes began to indicate the umlauted vowels.This approach was taken up and expanded by Herbert Penzl (1949), while the allophone theory in connection with i-umlaut was elaborated by other scholars, Marchand (1956)  and Moulton (1961) among others.
This traditional or 'classic' interpretation rests on two assumptions.The first is that the Old and Middle High German periods differed greatly in the representation of the umlauted vowels and diphthongs.This notion may have been prompted by the normalized symbols used in grammars and handbooks, but the actual practice of contemporary scribes shows that there was no great discontinuity between the Old High German and the Middle High German situation, so that for a long time the umlauted vowels continued to be represented with the letters used for the non-umlauted vowels.The confusion between umlauted and non-umlauted vowels shows that the letters of the Latin alphabet were slowly and gradually adapted to the needs of the German language, and that this process of adaptation was probably to a certain extent delayed by the fact that in many instances there was morphological alternation between forms with non-umlauted vowels and forms with umlauted vowels -for example in OHG holz -holzir (actually hölzir) -, so that the forms with umlauted vowels were orthographically associated with the corresponding non-umlauted vowels (as holz in our example) -see Cercignani 2022b.
The second assumption on which the traditional interpretation rests is that the new allophones became phonemes when the relevant sounds in the following syllable changed or disappeared.A serious objection to this view is that the change or loss of the conditioning factors would result in the loss of the relevant allophones.For if a phone is actually conditioned, the change or loss of the conditioning factors results in its reversal to the main phonetic features of the phoneme to which it belongs.
The obvious corollary is that if an alleged allophone does not disappear, it is because the relevant phone has already attained phonemic status.How, then, can an umlaut allophone attain phonemic status?Before examining the specific cases created by the Old High German i-umlaut phenomena, it is important to note that the factors which trigger off a change can be adduced to explain a diachronic phenomenon, not necessarily as conditioning factors in the synchronic analysis of the new situation created by the change itself.We should therefore distinguish between two aspects of phonological change: the diachronic phenomenon, which is triggered off by specific factors, and the resulting synchronic situation, which is determined by new systemic distinctions (e.g./o:/ vs. /ø:/) and new oppositions at a lexical level (e.g.schon vs. schön).
2.1.The i-umlaut of the back vowels resulted in a complete fronting of the original vowels.Obviously, we cannot reconstruct all the intermediate stages of the change, but we may assume that at an early stage the new phones would be somewhat advanced back vowels, a series of allophones that may be rendered with [u̟ :], [u̟ ], [o̟ :] and [o̟ ].However, at a later stage the new phones would have become front rounded vowels ([y:], [y], [ø:], [ø]), which would be clearly distinct from a whole series of unrounded front vowels (/i:/, /i/, /e:/, /e/) in the phonological system of the language.It was at this point that the new phones became phonemes, since in the front area there was now a systemic distinction between rounded and unrounded vowels.All this may be summarized as follows:
In the new situation the phonemic oppositions between the rounded front vowels and the unrounded front vowels were obviously present also at a lexical level in equivalent or nearly equivalent proximity (i.e.surrounding) contexts.
If we consider that in the Old High German period unstressed long vowels had probably become short in the spoken language, the above instance ōri ↔ ērī could in fact be adduced as a minimal pair, in addition to holī ↔ helī.
2.2.The Old High German i-umlaut produced similar results with regard to the relevant elements of the diphthongs /iu/, /uo/, /ou/.When these came to exhibit the rounded front values [y] and [ø], the new diphthongs attained phonemic status, in that they became systemically distinct from the pre-existing diphthong /ai/ > /ei/, which had unrounded front features in the second element.
In the new situation the phonemic oppositions between the new front diphthongs /iy/, /yø/, /øy/ and the diphthong /ai/ > /ei/ were obviously present also at a lexical level in equivalent or nearly equivalent proximity contexts.
Again, if we consider that in the Old High German period unstressed long vowels had probably become short in the spoken language, the above instance liuti ↔ leitī could in fact be adduced as a minimal pair, in addition to bruoten ↔ breiten.
In the new situation the phonemic oppositions between /ae:/ and /i:/, /e:/ were obviously present also at a lexical level in equivalent or nearly equivalent proximity contexts.