What is the origin of “long long /i/” i” before voiced consonants (the [ai] of wide, while, & tribe) versus “short long /i/” i” before unvoiced consonants (the [ʌi] of white, wife, & wipe)? When did this difference appear? Is it just a secondary distinction, or are there minimal pairs for these two diphthongs?
Obviously the distinction is not present in all accents—though its presence in most leads me to believe it's not a late arrival—and yet I've never found a dictionary that distinguishes them.
