Recent literature has sought to understand the presence of epenthetic vowels after the productions of postvocalic word-final consonants by second language (L2) learners whose first languages (L1s) restrict the presence of obstruents in coda position. Previous models include those in which epenthesis is seen as a strategy to mitigate the effects of coda licensing restrictions in the L1; others see epenthesis as a result of misperception of consonant releases in the L2 as indicating the presence of an additional syllable nucleus. The current study examines segmental identification and syllable counting in inexperienced Korean learners of English as a foreign language. Across stimuli, two effects were found. Increased perceptual epenthesis correlated with increased identification of a segment as voiceless, indicating a joint perception of voicelessness and an epenthetic vowel. Also, rate of epenthesis increased with accuracy of detecting sibilants and coronal segments, sounds characterized by salient consonant noise. Taken together, these results indicate a perceptual mechanism that evaluates segmental content and prosodic structure from an integrated percept. Analyses across individual listeners do not support a model in which perceptual epenthesis is a strategy to increase segmental accuracy; rather, they support models in which both syllable counting and segmental identification are skills that are reflections of increased proficiency in the L2. These results are discussed with respect to models of L2 phonology that rely on the robust encoding of lexical items.