Analysing spectral changes over time to identify articulatory impairments in dysarthria.

Identifying characteristics of articulatory impairment in speech motor disorders is complicated due to the time-consuming nature of kinematic measures. The goal is to explore whether analysing the acoustic signal in terms of total squared changes of Mel-Frequency Cepstral Coefficients (TSC_MFCC) and its pattern over time provides sufficient spectral information to distinguish mild and moderate dysarthric French speakers with Amyotrophic Lateral Sclerosis (ALS) and Parkinson's Disease (PD) from each other and from healthy speakers. Participants produced the vowel-glide sequences /ajajaj/, /ujujuj/, and /wiwiwi/. From the time course of TSC_MFCCs, event-related and global measures were extracted to capture the degree of acoustic change and its variability. In addition, durational measures were obtained. For both mild and moderately impaired PD and ALS speakers, the degree of acoustic change and its variability, averaged over the complete contour, separated PD and ALS speakers from each other and from healthy speakers, especially when producing the sequences /ujujuj/ and /wiwiwi/. Durational measures separated the moderate ALS from healthy and moderate PD speakers. Using the approach on repetitive sequences targeting the lingual and labial articulators to characterize articulatory impairment in speech motor disorders is promising. Findings are discussed against prior findings of articulatory impairment in the populations studied.

NORMATIVE DATA ON NASALANCE SCORES FOR FRENCH SPEAKING CHILDREN.

INTRODUCTION: The objectives of this study are to establish normative nasalance values in European French for children aged 8 to 10 years, to study the factors likely to influence nasalance values, and to ensure that the nasometer allows the differentiation of control subjects from subjects with velopharyngeal insufficiency. METHODS: Nasal balance scores were calculated using the Nasometer II 6450 (KayPENTAX) for 50 control subjects producing 31 verbal stimuli specifically designed for the French language. Nasalance scores were analyzed and compared with 7 subjects with velopharyngeal insufficiency. RESULTS: This study provided nasalance norms for each verbal stimulus. The phonetic content of the stimuli (nasality, vowel height, voicing) was a major factor influencing the nasalance score. However, the characteristics of the speaker (gender and age) had a non-significant effect, with the major exception of the presence or absence of velopharyngeal insufficiency. CONCLUSION: This study confirmed the need to use established normative values in the patient's language and for each verbal stimulus. Although the effect of vowel height on the nasalance score has been demonstrated, this study is the first to show an effect of voicing. Once normative nasalance scores are established, a validation study with a larger pathological population will be necessary. This study establishes normative nasalance scores in European French in children.

Validation of an objective assessment tool for velopharyngeal insufficiency in cleft lip and palate children.

The objective of this study is to utilize the Nasometer to objectively assess velopharyngeal competence, specifically through the quantification of nasalance. Initial calibration of the nasometer was conducted on American adults. The objective of this study was to validate the use of the nasometer for the objective diagnosis of velopharyngeal insufficiency (VPI) in French children born with a total cleft lip and palate and to select relevant verbal stimuli for clinical practice. MATERIAL AND METHODS: The nasalance scores of 42 children aged 8 to 10 years old, born with a cleft lip and palate, were collected and compared with 50 control children. The scores were then analyzed in relation to 31 verbal stimuli from the French corpus created for this study (sentences and syllables). The most relevant threshold values were determined by receiver operating characteristic curves, which exhibited the highest sensitivity and specificity. RESULTS: The results demonstrated statistically significant differences (p < 0.05) in the mean nasalance scores of the control and cleft groups for all verbal stimuli containing oral phonemes. Threshold values with good diagnostic accuracy were defined, and 15 verbal stimuli were selected for use in clinical practice. CONCLUSION: The nasalance threshold values defined in this study can be utilized for the objective diagnosis of velopharyngeal insufficiency (VPI) and the subsequent monitoring of French children aged 8 to 10 years old, born with a cleft lip and palate.

[Could speech rate of Wilson's disease dysarthric patient be improved in dual task condition?]. / Le débit de parole du patient wilsonien dysarthrique peut-il être amélioré en condition de double tâche?

INTRODUCTION: Dysarthria is one of the first sign of neurological Wilson's disease and is often characterized by a decreased speech rate. The aim of this study is to determine the abilities of Wilson's disease dysarthric patients to control their speech rate. We examined the impact of dual-tasking on the speech rate of patients as compared to healthy control speakers and in relation with their ability to accelerate speech rate when instructed to do so. METHODS: Twenty-six patients and twenty-six age- and sex-matched healthy controls repeated a sentence during 20 seconds at a comfortable speech rate used as reference. They were then asked to perform the same repetition task but in dual task conditions, in which sentence repetition was done while performing three types of executive grapho-motor tasks. Finally, the ability to control speech rate was tested by asking the speakers to perform the sentence repetition task alone but at a fast rate of speech. RESULTS: A significantly slower speech rate was observed for all patients as compared to controls. In the dual-task conditions, while the speech rate of healthy speakers accelerated significantly, two behaviors are found for the patients. Forty-two percent of the patients reproduced the control pattern with a significant increased in speech rate, while the other group significantly decreased their speech rate. Comparison of the ability of the two groups to intentionally modulate speech rate, when instructed to accelerate, shows that significantly better acceleration was achieved by speakers in the former group compared with the latter. CONCLUSIONS: This study supports the finding that patients with Wilson's disease exhibit an impaired speech rate and also impaired control of speech rate. Indirect assessment of speech rate modulation with the help of a dual-task paradigm has proven to be useful to distinguish patient behaviors. This paradigm could also be envisioned as a tool for rehabilitation.

Articulatory strengthening at edges of prosodic domains.

In this paper it is shown that at the edges of prosodic domains, initial consonant and final vowels have more extreme (less reduced) lingual articulations, which are called articulatory strengthening. Linguopalatal contact for consonants and vowels in different prosodic positions was compared, using reiterant-speech versions of sentences with a variety of phrasings read by three speakers of American English. Four prosodic domains were considered: the phonological word, the phonological (or intermediate) phrase, the intonational phrase, and the utterance. Domain-initial consonants show more linguopalatal contact than domain-medial or domain-final consonants, at three prosodic levels. Most vowels, on the other hand, show less linguopalatal contact in domain-final syllables compared to domain-initial and domain-medial. As a result, the articulatory difference between segments is greater around a prosodic boundary, increasing the articulatory contrast between consonant and vowels, and prosodic domains are marked at both edges. Furthermore, the consonant initial strengthening is generally cumulative, i.e., the higher the prosodic domain, the more linguopalatal contact the consonant has. However, speakers differed in how many and which levels were distinguished in this way. It is suggested that this initial strengthening could provide an alternative account for previously observed supralaryngeal declination of consonants. Acoustic duration of the consonants is also affected by prosodic position, and this lengthening is cumulative like linguopalatal contact, but the two measures are only weakly correlated.