While that sort of analysis probably isn’t impossible, it is computationally unrealistic to do in realtime on a language which wasn’t designed for it.
It’s the sort of thing which is simple in 99% of cases, but the last 1% might well be impossible. Sadly it’s the last 1% you need to worry about, because anyone trying to defeat your system is going to find them
Why shouldn’t they? Nose and toes do rhyme.
It’s possible there’s some accent I can’t immediately think of where they don’t, but all of the accents which come to mind use the same sound in both cases