Evaluating Nasalance Values Among Bilingual Mandarin-English Speakers.

OBJECTIVE: The goals of this research are (1) to establish normative nasalance values for bilingual Mandarin-English speakers and compare values to those of previously reported monolingual Mandarin speakers, and (2) to examine whether sex, age, dialect, and language proficiency affect levels of nasalance among Mandarin-English speakers in both English and Mandarin. DESIGN: All participants recorded the speech stimuli, constructed to include oral sentences, nasal sentences, oronasal sentences, and vowels /ɑ, i, u/ in Mandarin and English. Nasalance measurements were recorded using the Nasometer II 6450. PARTICIPANTS AND SETTING: A total of 45 (20 males and 25 females) native Mandarin speakers between 20 and 54 years of age from mainland China participated in the study. RESULTS: Mean nasalance scores of the Mandarin oral sentence (Mean [M] = 17.64, standard deviation [SD] = 7.33), oronasal sentence (M = 54.62, SD = 7.81), and nasal sentence (M = 68.73, SD = 8.09) are reported. Mean nasalance scores of the English oral sentence (M = 20.02, SD = 7.83), oronasal sentence (M = 58.71, SD = 7.59), and nasal sentence (M = 65.27, SD = 7.45) are reported. A repeated measures analysis of variance showed significant sex difference in nasalance scores for English stimuli ( P = .031) and Mandarin stimuli ( P = .040). There was no significant effects of age, dialect, and language proficiency on Mandarin or English stimuli. CONCLUSIONS: This is the first study to report normative values for Mandarin-English speakers using the Nasometer II. Values reported can be used for objective assessment of bilingual speakers.

Effect of motor-based speech intervention on articulatory placement in the treatment of a posterior nasal fricative: a preliminary MRI study on a single subject.

BACKGROUND: Posterior nasal fricatives are a learned compensatory articulation error and commonly substituted for oral fricatives. Treatment of such articulation errors requires the modification or teaching of skilled movements. A motor-based approach is designed to teach the complex motor skill movement sequences required in the production of sounds. Although motor learning research is well established, little has been done to determine how the approach changes the underlying physiology of articulatory movements. While the underlying anatomical configuration of the posterior nasal fricative has been described, no studies have quantified anatomic and physiological changes pre- and post-treatment. AIMS: To use magnetic resonance imaging (MRI) to visualize and quantify the results of motor-based speech-intervention approach on articulatory placement for the treatment of the posterior nasal fricative. METHODS & PROCEDURES: A 6-year-old male with a history of ear infections and posterior nasal fricative substitution for /s/ underwent six 1-h sessions of a motor-based treatment approach over the course of 2 weeks. Pre- and post-treatment evaluation included perceptual and instrumental assessment of speech and resonance. Perceptual resonance was rated by two speech-language therapists and articulation was assessed at the single-word level. Instrumental assessment included the See-Scape, Nasometer II and MRI during the sustained phonation of /s/. Amira v5.6 Visualization and Volume modelling software used the midsagittal and oblique coronal plane to measure dimensions of the articulatory anatomy. OUTCOMES & RESULTS: Interrater reliability was assessed using a Pearson product moment correlation (α = .05) and ranged from r = .91 to .95. Intra-rater reliability was assessed using the intra-class correlation coefficient (.976) demonstrating a high degree of reliability with a 95% confidence interval. Articulation improved from 0% accuracy for /s/ in isolation at baseline to 100% for /s/ at the word level and 95% accuracy during conversational speech by session 6. Post-treatment results from this study revealed a greater shortening of the levator veli palatini (levator) muscle length during articulatory movements, more pronounced velar knee and dimple, decreased velar thickness, increased velar length and altered tongue position. CONCLUSIONS & IMPLICATIONS: This study demonstrated the use of pre- and post-treatment imaging methodology to quantify articulatory changes following an intensive motor-based treatment approach. MRI demonstrated quantifiable changes in articulatory placement. Individuals who exhibit non-developmental and phoneme-specific articulation errors, such as the posterior nasal fricative, may be excellent candidates for short-term, intensive and frequent speech therapy sessions to remediate the production of the posterior nasal fricative.