Doubt and debit:
The ‘b’ in ‘doubt’ has no sound, just like the ‘b’ in ‘thumb’ or ‘dumb.’ ‘Doubt’ has the same vowel sound as ‘out.’ It’s only one syllable.
The ‘b’ in ‘debit,’ on the other hand, is pronounced. It’s a two-syllable word, and the first syllable is stressed.
‘Pronunciation’ doesn’t rhyme with ‘pronounce’ or ‘bounce.’ The first vowel sound is the same as in ‘one’ ‘fun,’ or ‘done.’