NGUYỄN Quốc Dũng


Department of Special Education and Rehabilitation, University of Cologne


Frequency of Phonemes in Southern Vietnamese Texts and its Contribution to Developing Speech Tests for Patients with Hearing Impairments


The frequency of phonemes in a specific language is crucial data that audiologists or pathologists need in order to develop valid materials for examining communication disorders such as hearing impairments or articulation disorders. These speech materials should have phoneme statistics that correspond to the frequency in the particular language, thus a knowledge of phoneme frequency helps audiologists and pathologists to select appropriate words in order to arrange them into speech tests. This study investigates the frequency of various phonemes in Southern Vietnamese text in different positions in the syllable: onset, prevocalic, nucleus and coda. Our research is an initial preparation for constructing an Adaptive Auditory Speech Test (AAST), to be used in evaluating the hearing ability of speakers of Southern Vietnamese. Texts collected from different sources included 157,025 monosyllabic words with 424,175 phonemes. These words were transcribed using IPA transcription. The frequency analysis shows that /a/ was the most frequently occurring vowel and /ŋ/ was the most frequently occurring consonant, whereas the vowel sound /uo/ and the consonant sound /ɣ/ were less frequent. Overall, the percentage of vowel phonemes was 46.3%, while consonant phonemes made up 53.7% of the Vietnamese text. Based on the obtained result, we could distribute 24 selected words into four sub-tests of AAST which included six disyllabic words in each test, corresponding to its frequency in Southern Vietnamese.