Acquisition of vowel articulation in childhood investigated by acoustic-to-articulatory inversion.

While the acoustical features of speech sounds in children have been extensively studied, limited information is available as to their articulation during speech production. Instead of directly measuring articulatory movements, this study used an acoustic-to-articulatory inversion model with scalable vocal tract size to estimate developmental changes in articulatory state during vowel production. Using a pseudo-inverse Jacobian matrix of a model mapping seven articulatory parameters to acoustic ones, the formant frequencies of each vowel produced by three Japanese children over time at ages between 6 and 60 months were transformed into articulatory parameters. We conducted the discriminant analysis to reveal differences in articulatory states for production of each vowel. The analysis suggested that development of vowel production went through gradual functionalization of articulatory parameters. At 6-9 months, the coordination of position of tongue body and lip aperture forms three vowels: front, back, and central. At 10-17 months, recruitments of jaw and tongue apex enable differentiation of these three vowels into five. At 18 months and older, recruitment of tongue shape produces more distinct vowels specific to Japanese. These results suggest that the jaw and tongue apex contributed to speech production by young children regardless of kinds of vowel. Moreover, initial articulatory states for each vowel could be distinguished by the manner of coordination between lip and tongue, and these initial states are differentiated and refined into articulations adjusted to the native language over the course of development.

Articulation rate: effects of age, fluency, and syntactic structure

(Reportamos los hallazgos básicos sobre los efectos del índice de articulación, derivados de la investigación experimental sobre la planificación de oraciones de los niños. Los experimentos fueron diseñados para evaluar los procesos de producción con atención a las variables sintácticas, a la vez que se controlaban las variables léxicas y fonológicas. Las mediciones del índice de articulación reflejaron que: (1) los índices difirieron entre niños (de 3 a 8,11) y adultos, donde los índices de los adultos fueron considerablemente más rápidos que los de los niños; (2) los efectos de la expresión de fluidez y falta de fluidez del sujeto sobre las subseries de fluidez difirieron para adultos y niños; y (3) el patrón del índice de articulación para las oraciones de relativo y las oraciones coordinadas difirió tanto de un tipo de oraciones a otro como dentro del grupo de edad (AU)

We report basic findings on articulation rate effects derived from experimental research on children's sentence planning. The experiments were designed to evaluate production processes with attention to syntactic variables while controlling for lexical and phonological variables. Articulatory rate measures showed (1) rates differed for children (3–8.11) and adults, with adult rates significantly faster than child rates; (2) the effects of fluent and dysfluent host utterances on fluent substrings differed for adults and children; (3) rate patterns for relative clause and conjoined clause utterances differed, both from each other and across age group (AU)

Revisión del concepto de eficacia en el tratamiento vocal de las enfermedades neurodegenerativas / Revising the concept of efficacy in the vocal therapy of neurodegenerative diseases

El tratamiento de los trastornos de la voz en las enfermedades neurodegenerativas es un tema muy controvertido, ya que no es posible esperar ni que la función se recupere totalmente, ni que las mejorías derivadas del tratamiento se mantengan a largo plazo. Es por ello que programar el tratamiento de la voz en estos trastornos implica replantearse el concepto de eficacia, ya que en estas personas no es posible conseguir logros permanentes. Sin embargo, actualmente existen estudios que demuestran resultados funcionales que permiten mantener por más tiempo una mejor calidad de vida. En este trabajo se ha revisado el estado actual de la literatura sobre el concepto de eficacia en el tratamiento de los problemas vocales de las enfermedades neurodegenerativas, analizando una serie de factores que favorecen esta eficacia y propician una mayor y más permanente disminución de la limitación funcional. Entre los factores propuestos cabe señalar la precocidad en la intervención, la jerarquización sistemática de objetivos terapéuticos y la diversificación de recursos. Asimismo se han seleccionado los protocolos de intervención para paliar los 3 tipos de déficits fonorrespiratorios más comunes en este tipo de enfermedades, esto es: la insuficiencia fonorrespiratoria, la incoordinación fonorrespiratoria y las disfunciones laríngeas. La eficacia de las tareas propuestas ha sido avalada en la literatura, bien por la medicina basada en la evidencia, bien por la opinión de expertos (AU)

Treating voice problems in neurodegenerative diseases is a controversial topic due to the lack of expectations of achieving complete functional recovery or long-lasting improvement. Therefore, when planning voice therapy in these disorders, the concept of efficacy needs to be redefined, since permanent improvements cannot be achieved in these patients. However, studies have been published that show more permanent functional benefits and improvements in quality of life of these persons. The present study was designed to review the state of the art on the vocal therapy of neurodegenerative diseases and to analyze the factors that enhance treatment efficacy and favor greater and longer-lasting reduction of functional limitations. Among the proposed factors to increase treatment efficacy are starting the intervention in the initial phases of the disorder, systematically planning the hierarchy of therapeutic targets, and implementing a multidimensional approach to different types of treatment resources. Additionally, a series of therapeutic protocols were selected to address the three main phonation deficits in neurodegenerative diseases, i.e. respiratory insufficiency, phonation incoordination and laryngeal dysfunction. All of the therapeutic strategies proposed in this study have been documented as being target efficient by either scientific evidence or expert opinion (AU)