ABSTRACT
UNLABELLED: The processes that take place during singing and acting are complex. However, morphologic and dynamic studies of the vocal tracts during speech have been gaining greater attention, mainly because of the rapid technical advances being made with magnetic resonance imaging (MRI) and image analysis and processing techniques. OBJECTIVES/HYPOTHESIS AND METHODS: Our aim was to describe the morphologic differences in the vocal tract resonance cavities among voice professionals using MRI, and with the three-dimensional models built from the MRI data, compare the volumes calculated for the whole vocal tract and its major resonance cavities. STUDY DESIGN: Prospective study. RESULTS: The images acquired during the spoken and singing tasks provided morphologic information about the whole vocal tract cavity and also its two major resonance cavities: the oral and the pharynx cavities; differences were observed in the volumes measured during the production of some vowels. CONCLUSIONS: The morphologic differences found in the singing voices indicated an increase in the oral cavity volume, resulting in an increase in the overall volumes measured. In the acting voices, both the resonance cavities of the vocal tract contributed to the differences measured.
Subject(s)
Glottis/anatomy & histology , Magnetic Resonance Imaging , Singing , Speech , Adult , Biomechanical Phenomena , Female , Glottis/physiology , Humans , Image Interpretation, Computer-Assisted , Imaging, Three-Dimensional , Male , Middle Aged , Models, Anatomic , Mouth/anatomy & histology , Mouth/physiology , Pharynx/anatomy & histology , Pharynx/physiology , Phonation , Prospective Studies , Speech Acoustics , Speech Production Measurement , Time Factors , Vocal Cords/anatomy & histology , Vocal Cords/physiology , Voice QualityABSTRACT
Over the last few decades, researchers have been investigating the mechanisms involved in speech production. Image analysis can be a valuable aid in the understanding of the morphology of the vocal tract. The application of magnetic resonance imaging to study these mechanisms has been proven to be reliable and safe. We have applied deformable models in magnetic resonance images to conduct an automatic study of the vocal tract; mainly, to evaluate the shape of the vocal tract in the articulation of some European Portuguese sounds, and then to successfully automatically segment the vocal tract's shape in new images. Thus, a point distribution model has been built from a set of magnetic resonance images acquired during artificially sustained articulations of 21 sounds, which successfully extracts the main characteristics of the movements of the vocal tract. The combination of that statistical shape model with the gray levels of its points is subsequently used to build active shape models and active appearance models. Those models have then been used to segment the modeled vocal tract into new images in a successful and automatic manner. The computational models have thus been revealed to be useful for the specific area of speech simulation and rehabilitation, namely to simulate and recognize the compensatory movements of the articulators during speech production.
Subject(s)
Larynx/physiology , Magnetic Resonance Imaging , Mouth/physiology , Phonation , Automation , Humans , Models, StatisticalABSTRACT
OBJECTIVES/HYPOTHESIS: The most recent and significant magnetic resonance imaging (MRI) improvements allow for the visualization of the vocal tract during speech production, which has been revealed to be a powerful tool in dynamic speech research. However, a synchronization technique with enhanced temporal resolution is still required. STUDY DESIGN AND METHODS: The study design was transversal in nature. Throughout this work, a technique for the dynamic study of the vocal tract with MRI by using the heart's signal to synchronize and trigger the imaging-acquisition process is presented and described. The technique in question is then used in the measurement of four speech articulatory parameters to assess three different syllables (articulatory gestures) of European Portuguese Language. RESULTS: The acquired MR images are automatically reconstructed so as to result in a variable sequence of images (slices) of different vocal tract shapes in articulatory positions associated with Portuguese speech sounds. CONCLUSIONS: The knowledge obtained as a result of the proposed technique represents a direct contribution to the improvement of speech synthesis algorithms, thereby allowing for novel perceptions in coarticulation studies, in addition to providing further efficient clinical guidelines in the pursuit of more proficient speech rehabilitation processes.
