2.1 Assessment of articulation and speech
Speech and articulation functions were evaluated using the Korean Speech Mechanism Screening Test designed to assess the structure and function of articulation and speech compared to the data of the normal Korean population.19
Tongue mobility was assessed by the limitation of lingual motions (Table 1). Each tongue motion was assessed with a score of 0 (severe impairment), 1 (mild impairment), or 2 (normal). The tongue mobility score was the sum of the 8 lingual motion scores. The maximal phonation time was performed twice, and the higher value was selected.
Articulation was assessed by having the patient read Korean poetry consisting of 39 syllables. The speech-language pathologist assessed the accuracy of /r/, /s/, and /z/ pronunciation with a score of 0 (severe impairment), 1 (mild impairment), or 2 (normal). The articulation score was defined as the sum of the 3 consonant scores.
The verbal diadochokinesis test was utilized to assess oral motor function.20 The patients pronounced the four sounds /pʌ/, /tʌ/, /kʌ/, /pʌtʌkʌ/, /rʌ/, /gn/, and /a/ as rapidly as possible for 5 seconds. This was repeated three times. The speech pathologist assessed the regularity (0-14) and accuracy (0-14) of each pronunciation with a score of 0 (severe impairment), 1 (mild impairment), or 2 (normal). The verbal diadochokinesis score was defined as the sum of regularity and accuracy score.
Reading speed was evaluated by having the patients read Korean poetry consisting of 60 syllables, and 18.2 seconds or more was considered abnormal in adults.