JCPSLP November 2016

such as bầm , bu , má , mạ , mệ , mợ , and u ; • be used currently in the speech of people within Viet Nam. For example, the traditional word for box was rương ; however, it was not selected because hộp or thùng is used more commonly now; • be culturally sensitive in both word choice and picture. For example, the word đũa (chopsticks) was selected rather than dao (knife) because seeing an image of a knife may scare young children; • be picturable so young children can recognise the word easily and spontaneously name the word. The images were considered to be contrastable to differentiate meanings. For example, the word gà (chicken) was selected for the initial consonant / ɣ / so the word chim (bird) was not selected for the initial consonant /c/ because of the possible confusion between these two images. Another example, the word phở (thinly sliced noodle soup) was seen as a good word choice containing the initial consonant /f/ but was not selected because of the possible confusion with the word bún (round noodle soup); • be selected from basic syntactic forms such as nouns (66 out of 77 words) and verbs (11 out of 77 words). Presentation The VSA consists of 77 monosyllabic words represented by 77 colour pictures. The order of the word list was based on initial consonants. Proposed prototypes for the 77 pictures were discussed by the VSA authors, then were sent to a Vietnamese artist to be drawn. The 77 pictures were bound in a picture booklet. The front page displays a picture illustrating a word and the orthography of the word (see Figure 2). On the back page, there is a small picture of the word plus full phonetic transcriptions of Standard Vietnamese, Northern, Central, and Southern Vietnamese as well as the prompts to elicit the word (see Figure 3). Test administration The VSA was designed to be administered in a standardised manner. The assessment can be administered in research and clinical settings. Instructions will be

Northern, Central and Southern dialects was collated based on an extensive literature review (Pha. m & McLeod, 2016). The following Vietnamese speech sounds were included in the VSA based on the review: • 23 initial consonants in Standard Vietnamese /p, b, t̪ ʰ , t, d, ʈ , c, k, ʔ , m, n, ɲ , ŋ , f, v, s, ʂ , z, ʐ, , x, ɣ , h, l/ and four variants including /ts, r/ in the Northern dialect and /w, j/ in the Southern dialect; • 6 final consonants in Standard Vietnamese /p, t, k, m, n, ŋ / and four variants across three dialects /c, ɲ , k p , ŋ m /; • 2 final semivowels /w, j/; • 1 medial semivowel/approximant /w/ in Standard Vietnamese and three dialects; • 16 vowels in Standard Vietnamese (including nine long singleton vowels /i, e, ɛ , ɯ , u, o, ɔ , ɤ , ɑ /, four short singleton vowels / ɑ̆ , ɤ̆ , ɛ̆ , ɔ̆ /, three diphthongs /ie, uo, ɯɤ /, and ten variants / ĭ , ɨ , ĕ , ŏ , ŭ , ɔː , oː , uː , ɛː , ɤː / across three dialects; • 6 tones in Standard Vietnamese and two variants of the tone 5 and 6 occurring in syllables ending by voiceless plosive consonants /p, t, k/ in three dialects. Elicitation of each Vietnamese speech sound Typically each speech sound is elicited in between one and five stimuli in single word sampling tools (McLeod, 2012b). Researchers have recommended there be at least two words in a single word task containing each phoneme in order to determine the consistency of production or phoneme stabilisation (Eisenberg & Hitchcock, 2010; Hua, 2002). Therefore, at least two stimuli were selected for each phoneme (consonants, vowels, and tones) shared across all dialects in the VSA. For example, the two selected words beginning with /k/ that were pronounced consistently across all dialects were: kẹo (candy) / kɛw 6 /, and cổ (neck) /ko 4 /. The authors attempted to avoid excessive use of any consonant, vowel, or tone within the word list. The selection of words also took into consideration different phonetic contexts in Vietnamese. Different phoneme sequence constraints were considered so as to accommodate variability in terms of syllable shapes, rimes, phonotactic variants, and tones within the child’s production rule system. It was important to accommodate the effect of coarticulation of front and back vowels on the production of initial and final consonants (Cao, 2006; Đoàn, 2003). Therefore, it was decided that the two words in the VSA containing the same initial consonants should be followed by a front and back vowel. For example, the selected words beginning with the initial consonant /b/ contained a front vowel bí (pumkin) /bi 5 /, and back vowel bảng (board) /b ɑŋ 4 /. In addition, the VSA authors considered the effect of coarticulation of rounded and unrounded vowels on the production of final consonants /k, ŋ / with back vowels (Cao, 2006; Đoàn, 2003). For example, the word bụng (belly) /b ŭŋ m6 / was added to the set of words beginning with initial consonant /b/. Word selection Within the VSA the selected words met following criteria. They had to: • be within the vocabulary range of Vietnamese-speaking children in Viet Nam, Australia, and USA so that children can produce the word spontaneously as often as possible; • be used frequently by the entire population throughout Viet Nam. Therefore, words having lexical variants were excluded. For example, the word m ẹ (mother) was not selected because of variants used in different regions

Figure 2. The front page for the stimulus item nón (cone hat).

Figure 3. The back page for the stimulus item nón (cone hat).

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JCPSLP Volume 18, Number 3 2016

Journal of Clinical Practice in Speech-Language Pathology