Two sounds close enough to trade places: the “ih” of ship and the “uh” of banana. Swap one for the other and a different word comes out — this page is how to keep them apart, in both directions.
Bring the tongue slightly higher and further forward than a neutral mumble — a short, light vowel near the front of the mouth.
“Close, bello, but the vowel fell asleep in the middle of your mouth! Wake it up — tongue forward, small and bright: ih!”Nunzio, when he hears it
You cannot hear your own swap. That is the whole problem.
Nunzio records you reading a sentence, scores every sound in it on your phone — nothing is uploaded — and tells you which of these two actually came out. Nunzio — Accent Coach is coming to the App Store and Google Play.