Perception of Italian and Japanese singleton/geminate consonants by listeners from different backgrounds

We investigated if and how the use of one or multiple languages (bilingualism hereafter) affects the perception of intervocalic singleton/geminate consonants in Italian and Japanese. Two groups of non-native listeners (monolingual speakers of Australian English and bilingual speakers of Cantonese/English or Vietnamese/English) were examined. Two groups of native listeners (Italian and Japanese) residing in Australia acted as controls. Our aim was to test the hypothesis that the bilinguals process unfamiliar sounds more efficiently than the monolinguals due to their expanded phonetic inventories. Results showed that bilingualism did not result in superior performance overall. However, while the monolinguals identified consonant length in Italian slightly more accurately (albeit nonsignificantly) than in Japanese, the bilinguals showed the opposite pattern, i.e. greater accuracy with Japanese than with Italian. Generally, bilingual and monolingual non-native listeners misperceived geminates as singletons more often than they misperceived singletons as geminates in Japanese, but not in Italian.