Written by Dyami Millarson
The Old Norse ey occurs in words such as gleyma to forget, deyja to die and the well-known theonyms Freyja and Freyr. To know the pronunciation of Old Norse ey, we need to take a look at (1) the etymology of ey, (2) the historical spellings of ey, and (3) the descendants of ey.
Ey comes from au via i-umlaut. Consequently, Old Norse ey always corresponds with áu in Gothic. Gothic áu is a falling diphthong and hence ey must be a falling diphthong as well. In falling diphthongs, the last element is pronounced with more obstruction in the mouth, i.e., pronounced more like a semivowel. In rising diphthongs, the first element is pronounced with more obstruction in the mouth, i.e., peonounced more like a semivowel.
Ey actually stands for øy. Ey was written as oy in old manuscripts. This means that the first element of the diphthong was rounded, not unrounded, i.e., it was in harmony with the second element in terms of roundedness.
Ey corresponds to øy in Norwegian, ö in Swedish, ä and e in Elfdalian, øj and e in Danish, oy and ey in Faroese, and ey in Icelandic where it has phonetically merged with the Icelandic ei. All the descendants of the ey which are diphthongs rather than monophthongs are falling – not rising – diphthongs. This is further confirmation that ey was a falling diphthong.
The Norwegian øy, which is pronounced as [œʏ̯], is phonetically the closest to the Old Norse ey among all of the descendants of the Old Norse falling diphthong. It occurs in words such as døy to die, gløyme to forget, and øyne eyes.
However, the pronunciation of the Norwegian øy is not identical to that of Old Norse ey. Particularly for the second element of the Old Norse diphthong, we may turn to Dutch for guidance. Dutch bas the falling diphthong ui, which is considered notoriously difficult by foreigners while it is pronounced as [œy̯].
The non-syllabic [y̯] is pronounced with more obstruction than the preceding syllabic vowel, making it like the semivowel [ɥ]. If one were to pronounce ui as [œɥ] in Dutch, this would sufficiently sound like [œy̯] to Dutch ears, and so the difference between the non-syllabic vowel [y̯] and the semivowel [ɥ] is negligible. The Old Norse y in ey may be compared to the semivowel [ɥ] for similar reasons, but it ought to be borne in mind that it was in all likelihood a non-syllabic vowel like the second element of øy is in Norwegian.
The second element of Old Norse ey should have been pronounced identically to the second element of the Dutch ui (old spelling: uy), i.e., as a non-syllabic rounded close front vowel [y̯]. The first element may, however, have been pronounced as a close-mid vowel [ø]. We would thus end up with [øy̯], which sounds like Finnish öy, as the pronunciation of ey. Regionally, however, the pronuncuation of ey may have shifted more towards the Dutch-like [œy̯] early on as the Norwegian, Swedish, Danish, and Elfdalian descendants of Old Norse ey seem to suggest. The difference between [ø] and [œ] is slight, and thus variation between them could already have arisen early on. The pronunciation of Faroese, and Icelandic descendants, nevertheless, suggest that the first element of ey had an [e]-like quality, and thus it must have sounded like [ø] rather than [œ] if it was rounded.
So is [œy̯] or [øy̯] elder? Which is the original pronunciation of ey? The strongest evidence in favour of the former comes from Norwegian, which is descended from Old West Norse. Curiously, the Old East Norse-descended Swedish and Elfdalian seem to suggest descendance from [œy̯] as well. However, Old East Norse-descended Danish and Old West Norse-descended Faroese and Icelandic really seem to suggest [øy̯]. If Old Norse ey developed into Faroese and Icelandic sounds which are closer to [øy̯] than [œy̯] yet Old Norse ey developed into Norwegian, Swedish, Danish and Elfdalian sounds which are closer to [œy̯] than [øy̯], and if we classify Icelandic and Faroese as Insular North Germanic and Swedish, Danish, Norwegian, and Elfdalian as Continental North Germanic, we can conclude that sounds closer to [œy̯] are typically Continental North Germanic and sounds closer to [øy̯] are typically Insular North Germanic, and so a historical division of [œy̯] and [øy̯] along the lines of West and East Norse is troubled by the North Germanic descendants of ey.
Etymology may offer a clue as to whether [œy̯] or [øy̯] is elder. The Old Norse au is actually ou or ǫu. Au had already shifted to ou/ǫu by the time ey emerged. So ey actually comes from this ou/ǫu, not from the original au. If ey had come directly from the original au in Old West Norse, it could originally have been pronounced [œy̯]. However, ey most certainly came from ou/ǫu in Old West Norse, and so the original Old West Norse pronunciation of ey must be [øy̯], which is also reflected by the Icelandic and Faroese and which defeats the whole assumption based on Norwegian that [œy̯] might be elder.
What if the Norwegian [œy̯] were the result of influence from East Norse? After all, the ey-descended sounds of Danish, Swedish and Elfdalian are pretty close to [œy̯]. The assumption that the Norwegian [œy̯] is East Norse makes some historical sense. Norway stood under Danish influence for a long time in its history. I have not studied au and ey sufficiently in Old East Norse to offer a definitive judgement on the situation there: if the a in Old East Norse au were unassimilated (i.e., not u-umlauted) by the time of the emergence of ey/oy in Old East Norse, the Old East Norse pronunciation may have been [œy̯], which could then be used to explain the Continental North Germanic descendants. Please bear in mind, the whole point of trying to pinpoint whether the occurrence of [œy̯] and [øy̯] may have been distributed along the lines of East and West Norse is to find out whether [œy̯] or [øy̯] is elder and whether [œy̯] and [øy̯] might have been synchronous realisations of ey during the Old Norse period.
Hypothetically speaking, it might be that Norwegian has taken on a predominantly originally Old East Norse feature and that Old West Norse predominantly had [øy̯] - I say predominantly since the situation may have been fluid while Old West Norse and Old East Norse were very much alike and could easily adopt features from each other. A more or less fluid geographic distribution does, nevertheless, not tell us which of the two pronunciations is elder. Howeven, given that an original [œy̯] is falsified for Old West Norse, we may call [œy̯] into question for Old East Norse as well.
Hypothetically speaking, it is equally possible that both Old West Norse and Old East Norse had [øy̯] originally and that this sound developed into [œy̯] on the continent and remained [øy̯] on the islands. I find this hypothesis the most plausible. We must not forget that more than a millennium has passed since the Old Norse au, which was actually ou/ǫu, had shifted to ey, and so it is logical to expected a sound shift of [øy̯] > [œy̯] as seen in Norwegian. It is actually remarkable how close the Norwegian diphthong is to the original Old West Norse one even after all this time. [œy̯] must have been an intermediate stage in Norwegian before the sound shifted to its currwnt form, and so we can assume that [œy̯] is a later stage of [øy̯], which means [œy̯] is presumanly younger and [øy̯] presumably elder.
In any case, we know now – through etymology – that the original Old West Norse pronunciation is [øy̯]. When people study Old Norse, they most commonly study Old West Norse (the Norse of Norway) instead of Old East Norse (the Norse of Sweden and Denmark) and Old Gutnish (the Norse of Gotland which forms a separate banch from Old West Norse and Old East Norse), and so most students of Old Norse would be satisfied with knowing the original Old West Norse pronunciation of ey. It ought to be clear now how to pronounce Freyja and Freyr in the original manner. Knowing the original pronunciation does, nevertheless, not mean that the variant pronunciation [œy̯] could not already have occurred side by side with [øy̯] already from the earliest stages of the Old Norse ey. [œy̯] certainly seems a possible variation of [øy̯] as it deviates from the original only ever so slightly, and people in the Middle Ages – pretty much like they are now – generally were not that careful about the pronunciation of their vowels, and they certainly tolerated a certain degree of variation.