In Vowels^x, American English^x, Phonics^x

I don't think it's called intonation. It's allophonic vowel length: vowel phonemes are realized as longer vowel allophones before voiced consonant phonemes in the coda of a syllable. This is found in all dialects of American English. Some American dialects have some phonemic vowel distinctions...

It’s rather hard to work out quite what you are looking for here. Some of these features – as Marvin A was pointing out – are not specifically American English pronunciation, but the allophonic variation that occurs in connected speech. That is, the pronunciation of some sounds is influenced...