Is the pronunciation change from "woman" to "women" unique in English?

Solution 1:

In American English, woman is pronounced /'wʊmən/, and women is pronounced /'wɪmən/.
The only difference between them is the vowels in the first stressed syllable, /ʊ/ and /ɪ/.

/ʊ/ and /ɪ/ are very similar; they're both high lax vowels. The only difference between the two vowels is that singular /ʊ/ is a back high lax vowel and plural /ɪ/ is a front high lax vowel.

This situation -- having a back vowel in the singular and a front vowel in the plural --
is not at all unusual in English. It's the result of the old Germanic process of Umlaut,
which fronts vowels to anticipate front vowels in an ending. The same thing happened to
goose ~ geese, only with the high tense vowels /u/ and /i/, instead of high lax vowels.
Details in the link.