Investigation Of The Learning Trajectory Of Mandarin By Tibetan Speakers

When acquiring a spoken language,speakers adapt their speech organs to the articulatory manners and places and thus form a specific articulatory space.For second language(L2)learning,the acquisition process is essentially the one for the learners to approach the standard speech of native speakers in articulatory and acoustical domains by overcoming interferences from their first language.Based on this view,this study investigates learning trajectories in L2 acquisition by measuring the changes in the distance between vowel structures observed from L2 learners and the natives.The vowel(or consonant)structures were constructed by using the Laplacian eigenmaps.30 Tibetan Mandarin learners with three Mandarin proficiency levels and 10 Mandarin native speakers participated in this study.The results showed that: i)the higher the Mandarin proficiency of Tibetan speakers is,the closer the structure of their Mandarin vowels(or consonants)is to that of the natives,and ii)the learning trajectory of the six Mandarin vowels,except for vowel /o/,shows a monotonic tendency,that is,as the Tibetan speakers' Mandarin proficiency level increases,the distance reduces for each vowel.The trajectory of Mandarin vowel /o/ by Tibetan speakers shows some regression in the learning process of Mandarin,that is,Tibetan speakers with an intermediate level of Mandarin proficiency perform better than those with an advanced level in the production of Mandarin /o/.