Abstract
The study presented in this article is one of the attempts to find out whether adult learners can consistently distinguish unknown languages spoken by the same talker and thus whether they are subconsciously aware of the acoustic – phonetic characteristics of these languages in the pre-lexical stage of learning. It also seeks to find out if the learners’ L1 phonetic background may have any influence on the unknown language discrimination task. It is found out that the Filipino and Vietnamese listeners can generally perform above chance in the language discrimination task. Moreover, it is also revealed in the study that the Vietnamese students, whose L1 is a tonal language, performed better in the group with tone as a contrast feature. The findings serve as an evidence for the listeners’ ability to abstract language features from the talker voice characteristics in order to accomplish the language discrimination task. They also provide evidence to argue for the adaptation of the optimal silence period in the CLT to get the learner acquire the suprasegmental features of the target language in a more effective way. Finally, the study proves the influence of the learners’ L1 phonetic background on acquiring the acoustic – phonetic features of a foreign language.