Perception of silent-center syllables by native and non-native English speakers

The amount of acoustic information that native and non-native listeners need for syllable identification was investigated by comparing the performance of monolingual English speakers and native Spanish speakers with either an earlier or a later age of immersion in an English-speaking environment. Duration-preserved silent-center syllables retaining 10, 20, 30, or 40 ms of the consonant-vowel and vowel-consonant transitions were created for the target vowels /i, ɪ, eɪ, ε, æ/ and /ɑ/, spoken by two males in /bVb/ context. Duration-neutral syllables were created by editing the silent portion to equate the duration of all vowels. Listeners identified the syllables in a six-alternative forced-choice task. The earlier learners identified the whole-word and 40 ms duration-preserved syllables as accurately as the monolingual listeners, but identified the silent-center syllables significantly less accurately overall. Only the monolingual listener group identified syllables significantly more accurately in the duration-preserved than in the duration-neutral condition, suggesting that the non-native listeners were unable to recover from the syllable disruption sufficiently to access the duration cues in the silent-center syllables. This effect was most pronounced for the later learners, who also showed the most vowel confusions and the greatest decrease in performance from the whole word to the 40 ms transition condition.