I pronounce the first vowel sound exactly the same way in the singular and plural forms "woman" and "women". So I don't say "wimmin" in the plural (IYSWIM), I say "women", which basically means that I pronounce the singular and the plural the same, since the second vowel sound is not really differentiated as it is in "man" and "men" (nobody says "a wo-man" and "some wi-men"... or do they?). Not sure I'm making myself clear, hard to explain without phonetic alphabet. My colleagues here in France, in particular the English linguistics/phonetics specialists, are aghast that I a) mispronounce so basic a word and b) didn't know I was flouting a fundamental principle of pronunciation.
Have I just been blithely unaware of a basic rule of pronunciation for most of my life, or is my Scottishness an explanation? How do other Scottish MNers pronounce "women"? Does anyone know if there is an established Scottish pronunciation? I've always been really interested in languages and have a good ear, so I find it hard to believe I could have failed to notice throughout the first 20-odd years of my life (i.e. those spent in Scotland) that everyone except me pronounced "women" as "wimmin".