In tonal languages, tones are associated with both and phonological and lexical domains. Accurate tone articulation is required in order to convey the correct meaning. Learning tones at both word and phrase levels is often challenging for L2 learners with non-tonal language background, because of possible subtle difference between the close tones. In this paper, we discuss an adoption of StudyIntonation CAPT tools to the case of Vietnamese language being a good example of register tonal language with a complex system of tones comprising such features as tone pitch, its length, contour melody, intensity and phonation. The particular focus of this contribution is to assess the adoption of StudyIntonation course toolkit and its pitch processing and visualization algorithms in order to evaluate how the combined use of audio and visual perception mechanisms supported by StudyIntonation may help learners to improve the accuracy of their pronunciation and intonation with respect to tonal languages.