Detección automática de voz hipernasal de niños con labio y paladar hendido a partir de vocales y palabras del español usando medidas clásicas y análisis no lineal

RESUMEN: Este artículo presenta un sistema para la detección automática de señales de voz hipernasales basado en la combinación de dos diferentes esquemas de caracterización aplicados en las cinco vocales del español y dos palabras seleccionadas. El primer esquema está basado en características clásicas como perturbaciones del periodo fundamental, medidas de ruido y coeficientes cepstrales en la frecuencia de Mel. El segundo enfoque está basado en medidas de dinámica no lineal. Las características más relevantes son seleccionadas usando dos técnicas: análisis de componentes principales y selección flotante hacia adelante secuencial. La decisión acerca de si un registro de voz es hipernasal o sano es tomada usando una máquina de soporte vectorial de margen suave. Los experimentos consideran grabaciones de las cinco vocales del idioma español y las palabras y se consideran, asimismo, tres conjuntos de características: (1) el enfoque clásico, (2) el análisis de dinámica no lineal y (3) la combinación de ambos esquemas. En general, los aciertos son mayores y más estables cuando las características clásicas y no lineales son combinadas, indicando que el análisis de dinámica no lineal se complementa con el esquema clásico.ABSTRACT: This paper presents a system for the automatic detection of hypernasal speech signals based on the combination of two different characterization approaches applied to the five spanish vowels and two selected words. The first approach is based on classical features such as pitch period perturbations, noise measures, and Mel-Frequency Cepstral Coefficients (MFCC). The second approach is based on the Non-Linear Dynamics (NLD) analysis. The most relevant features are selected and sorted using two techniques: Principal Components Analysis (PCA) and Sequential Forward Floating Selection (SFFS). The decision about whether a voice record is hypernasal or healthy is taken using a Soft Margin - Support Vector Machine (SM-SVM). Experiments upon recordings of the five Spanish vowels and the words are performed considering three different set of features: (1) the classical approach, (2) the NLD analysis, and (3) the combination of the classical and NLD measures. In general, the accuracies are higher and more stable when the classical and NLD features are combined, indicating that the NLD analysis is complementary to the classical approach

Speech in Sri Lankan cleft palate subjects with delayed palatoplasty.

This investigation was undertaken within the context of the Sri Lankan Cleft Up and Palate Project, probably the largest surgical and research programme to date concerned with the late operated cleft lip and/or palate subject (Mars et al., 1990). This study examines the speech results of88 patients who received palatal surgery by a visiting British surgical team. The main cohort, consisting of 67 nonsyndromic cleft lip and/or palate Sinh ala speaking patients over the age of eight years at palate repair, have been studied longitudinally. All these patients have pre-operative, post-operative, and post-therapy speech recordings. In addition, 21 similar patients below the age of eight years at surgery have been partially examined. 51 patients have further speech recordings at 4 or 5 years post-operatively. Investigations of velopharyngeal function were undertaken using lateral skull X-rays of patients phonating "ee', nasopharyngoscopy, and a perceptual assessment. Post-operative intra-oral examinations were also carried out. A unique method of speech analysis has been devised, and is used to describe the speech results. The results have shown that patients who have established their speech with an unrepaired palate usually have severely disordered speech, with the exception of some patients with less severe clefts. Post-operatively, many patients retain these poor speech patterns, even with some speech therapy support. Post-therapy, only one third of the cohort had normal or near-normal speech, none of whom were adults. The value of palatal closure is very limited if regular speech therapy is not available as a follow-up to surgery. Only 20% of the cohort achieved post-operative velopharyngeal closure, suggesting that palatoplasty is an inadequate surgical procedure for the majority of patients, in particular those who present with major clefts and are older than eight years of age at surgery. The important variables affecting outcome are palatal repair, speech therapy intervention, age, cleft type, nature of pre-operative speech, and nature of surgery. Structural factors in particular velopharyngeal function and also possibly fistulae, in the adult group, are further relevant variables. Criteria for selecting patients for surgery within this type of environment are proposed

Master of Science

thesisThe purpose of this study was to examine the speech/language skills of children with cleft palate and their noncleft peers at 39 months, profile the speech/language outcomes of children with cleft palate at 39 months, and extend previous studies examining pre- and postsurgery speech/language skills that predict later speech/language outcomes of children with cleft palate at 39 months. Participants included 66 children, 43 children with cleft palate and 23 noncleft children. Spontaneous speech/language samples were collected at 9 months, postsurgery (approximately 13 months), 21 months, and 39 months of age in the child's home during an interaction with the caregiver. Speech and language measures were calculated using computer software programs and hand calculations. Children were classified into one of the four speech/language outcome profiles using descriptive statistics. Results of the between-group comparisons revealed the children with cleft palate had fewer consonant sounds, produced less accurate consonants for the majority of the place and manner categories, and had lower mean length of utterances than their noncleft peers. Within-group comparisons revealed the risk factors gender, maternal education, and resonance were associated with poorer speech outcomes for children with cleft palate at 39 months. The profile normal velopharyngeal mechanism and delayed speech and/or language had the highest membership (41%). Correlations between pre- and postsurgery measures and later speech/language outcomes at 39 months revealed negative correlations between 9 month predictors and all outcome measures. All other predictors were positively correlated with the speech outcome measures at 39 months. True consonant inventory and stop production measures at 21 months were the best predictors of the profile normal velopharyngeal mechanism and normal speech/language. These results suggest that children with cleft palate have poorer speech/language outcomes than noncleft peers at 39 months of age. There is a need for children with cleft palate to receive earlier speech/language intervention to help them catch up with their noncleft peers. Finally, the strongest correlations were found between true consonant inventory and stop production at age 21 months, suggesting that 21 months is the best predictive age for speech and language outcomes at 39 months

A feasibility study of visual feedback speech therapy for nasal speech associated with velopharyngeal dysfunction

Nasal speech associated with velopharyngeal dysfunction (VPD) is seen in children and adults with cleft palate and other conditions that affect soft palate function, with negative effects on quality of life. Treatment options include surgery and prosthetics depending on the nature of the problem. Speech therapy is rarely offered as an alternative treatment as evidence from previous studies is weak. However there is evidence that visual biofeedback approaches are beneficial in other speech disorders and that this approach could benefit individuals with nasal speech who demonstrate potential for improved speech. Theories of learning and feedback also lend support to the view that a combined feedback approach would be most suitable. This feasibility study therefore aimed to develop and evaluate Visual Feedback Therapy (VFTh), a new behavioural speech therapy intervention, incorporating speech activities supported by visual biofeedback and performance feedback, for individuals with mild to moderate nasal speech. Evaluation included perceptual, instrumental and quality of life measures. Eighteen individuals with nasal speech were recruited from a regional cleft palate centre and twelve completed the study, six female and six male, eleven children (7 to 13 years) and one adult, (43 years). Six participants had repaired cleft palate and six had VPD but no cleft. Participants received 8 sessions of VFTh from one therapist. The findings suggest that that the intervention is feasible but some changes are required, including participant screening for adverse response and minimising disruptions to intervention scheduling. In blinded evaluation there was considerable variation in individual results but positive changes occurred in at least one speech symptom between pre and post-intervention assessment for eight participants. Seven participants also showed improved nasalance scores and seven had improved quality of life scores. This small study has provided important information about the feasibility of delivering and evaluating VFTh. It suggests that VFTh shows promise as an alternative treatment option for nasal speech but that further preliminary development and evaluation is required before larger scale research is indicated

An ultrasound investigation of tongue dorsum raising in children with cleft palate +/- cleft lip

Objective: This study aimed to determine whether overuse of the tongue dorsum, or back, is evident in children with repaired cleft palate with or without cleft lip (CP+/-CL). We hypothesized that children with CP+/-CL would show overuse of the tongue dorsum, a compensatory pattern. Method: Secondary data analysis of mid-sagittal ultrasound tongue imaging data from 31 children with CP+/-CL and 29 typically developing children were used. We annotated the consonants /ʃ, t, s, k/ at the point of maximum constriction in an /aCa/ environment. Children with CP+/-CL said the tokens 10 times, typically developing children said them once. We automatically fitted splines to the tongue contour and extracted the Dorsum Excursion Index (DEI) for each consonant. This metric measures the relative use of the tongue dorsum, with more posterior consonants having higher values. We compared DEI values across groups and consonants using a linear mixed effects model. DEI was predicted by the interaction of consonant (baseline: /ʃ/) and speaker type (baseline: TD), including by-speaker random slopes for consonant and random intercepts for speaker. Results: Overall DEI was not higher in children with CP+/-CL compared to typically developing children. Between groups the only significant difference was the position of /k/ relative to /ʃ/, where the difference between these two consonants was smaller in the children with CP+/-CL. Conclusions: There was no support for the hypothesis that overuse of the tongue dorsum is a common characteristic in children with repaired CP+/-CL. However, individual children may present with this pattern

Application of Pattern Recognition Techniques to the Classification of Full-Term and Preterm Infant Cry

Objectives: Scientific and clinical advances in perinatology and neonatology have enhanced the chances of survival of preterm and very low weight neonates. Infant cry analysis is a suitable noninvasive complementary tool to assess the neurologic state of infants particularly important in the case of preterm neonates. This article aims at exploiting differences between full-term and preterm infant cry with robust automatic acoustical analysis and data mining techniques. Study design: Twenty-two acoustical parameters are estimated in more than 3000 cry units from cry recordings of 28 full-term and 10 preterm newborns. Methods: Feature extraction is performed through the BioVoice dedicated software tool, developed at the Biomedical Engineering Lab, University of Firenze, Italy. Classification and pattern recognition is based on genetic algorithms for the selection of the best attributes. Training is performed comparing four classifiers: Logistic Curve, Multilayer Perceptron, Support Vector Machine, and Random Forest and three different testing options: full training set, 10-fold cross-validation, and 66% split. Results: Results show that the best feature set is made up by 10 parameters capable to assess differences between preterm and full-term newborns with about 87% of accuracy. Best results are obtained with the Random Forest method (receiver operating characteristic area, 0.94). Conclusions: These 10 cry features might convey important additional information to assist the clinical specialist in the diagnosis and follow-up of possible delays or disorders in the neurologic development due to premature birth in this extremely vulnerable population of patients. The proposed approach is a first step toward an automatic infant cry recognition system for fast and proper identification of risk in preterm babies