INTERSPEECH 2007 Structural Assessment of Language Learners ’ Pronunciation

Speaker-invariant structural representation of speech was proposed [1], where only the phonic contrasts between speech sounds were extracted to form their external structure. The acoustic substances were completely discarded. Considering a mapping function between speaker A’s acoustic space and B’s space, the speech dynamics was mathematically proven to be invariant between the two irrespective of the form of the function [2]. This structural and dynamic representation was applied to describe the pronunciation of learners [3]. Since the nonlinguistic factors were removed effectively, the representation could highlighted the non-nativeness in the individual pronunciations. For vowel learning, it was automatically estimated for each of the learners which vowels to correct by priority [4]. Unlike the conventional approach, the estimation was done withou