Analyze Dynamic Characteristics Of Speech Individuality Based On MRI

Magnetic resonance imaging(MRI)techniques brought opportunities for further research in the field of speech in recent speech production studies.The relative tongue size is one of measurable indices to evaluate normal and pathological articulation,since it would predict the mobility of the tongue within the oropharyngeal cavity.This study analyzes static and dynamic magnetic resonance images(MRI)and examines the relationship between the index and tongue movement velocity during Chinese short words produced by five Chinese speakers(three female and two male adults).All the MRI data were corrected for head orientation with the palatal plane.The relative tongue size was defined on the static 3D data for vowel /i/ as the ratio of the tongue area to the total area of the tongue and oropharyngeal cavity.The tongue movement velocity was derived from combined cine-and tagged-MRI,the purpose of the image processing is to synthesize a new set of images that shows marker points on the oral and pharyngeal surface of the tongue.The tongue movement velocity was measured from time courses of tongue surface points marked by the tag lines on the tongue tissue.To represent the velocities on the oral and pharyngeal surfaces of the tongue separately,a few marker points were sampled on each surface to calculate the mean velocity.The comparison between the index and velocity for the male and female groups showed evidence that the smaller the tongue,the faster the tongue movement.This index infers a causal factor of individual articulatory difference and clarity of speech,also providing a hint to explore the nature of certain articulation disorders involving abnormal tongue size.