I'm going to propose that this phenomenon has nothing to do with voiceless stops. I think it's worth pointing out that [ɾ] is an allophone ... ... <看更多>

Phonemes and allophones · [tʰ] before stressed vowels (time) · [ʔt] in syllable codas (cat) · [ɾ] between vowels (city) · [ʧ] before [r] (tree) · [t] elsewhere (sty). ... <看更多>