The present study tests how focus prosody, conveying prosodic prominence, influences listeners' perception of segmental contrasts in speech. This question is pursued in light of the way in which focus prosody and accentuation cause segmental cues to vary. Two test cases are adopted: effects of accentuation on vowel formants via so-called sonority expansion, and effects of post-focus compression on vowel duration as a cue to coda obstruent voicing in American English. In two experiments, findings show that listeners adjust perception of both of these cues in line with how focus prosody changes their realization in speech production. In the case of vowel duration, the design of the experiment additionally considers how pitch and duration as vowel-intrinsic properties lend prominence and mediate the effect of contextual focus prosody. It is observed that intrinsic prominence influences how contextual prominence effects operate, where listeners only show the expected contextual influence of post-focus compression for a vowel that is intrinsically non-prominent. When this is not the case, domain-general effects on vowel duration perception related to pitch and durational context are evident. These findings show that the prosody of an utterance, conveying focus and prominence information, shapes perception of segmental cues, and further that listeners integrate intrinsic and contextual information in their perception of prominence in this domain.