@SpaceForDogs@todon.nl I haven't done any actual analysis with recordings or anything, but there is no noticeable difference in length in our dialect either. I'm guessing the (in)famous southern drawl leads to lengthening the vowel of my to where it approximately matches that of hi. You're right, though, they do have different length in General American, but vowel length is non-phonemic in English so they are still considered to rhyme.