MRI & CT Studies of the Developing Vocal Tract

描述(申请人提供)：构成声道的口腔和咽腔在从婴儿期到幼儿期和青春期的成长过程中经历了大小、形状和相对比例的变化。虽然声学理论表明，声道几何形状可以预测语音的频谱形状，但声道发育变化与语音声学变化之间的关系尚未得到充分研究。这是由于发育过程中声道解剖重构的定量信息匮乏所致。为了解决这个问题，我们设计了一种磁共振成像(MRI)程序来测量36个预定义的头部和颈部结构(Vorperian等人，1999)，并确保了一个包含300个典型病例和10个非典型病例(21三体)的成像数据库。这使得我们能够构建一个关于头部、面部和声道结构同时发育的独特测量数据库。我们的新发现表明，声道长度的发育遵循位于神经和躯体生长曲线中间的生长曲线；不同声道结构对其延长的相对贡献在发育过程中发生变化；在加速生长期间，硬组织和软组织结构中的同步生长持续存在。这个拟议的项目结合了成像、声学分析和几何建模，研究了声道从婴儿期到成年期的发展。这项拟议研究的目标是：(1)通过进行额外的线性和体积测量来扩展我们的测量数据库，并用代表特定声道解剖的声学测量来补充它；(2)对声道结构的个体和同步生长模式的一般趋势进行统计建模；(3)建立发育中声道的几何模型并计算共振峰频率；以及(4)将计算的共振峰数值与特定年龄的声学数据相关联，以推断发音器活动的发展模式。这些目标将通过我们的磁共振成像数据库和一个类似的计算机化断层扫描(CT)图像数据库来实现，该数据库覆盖了典型和非典型发展病例的整个发育期，并将得到保护。这一发现将对更好地理解语言发育的解剖学相关性具有理论和临床意义。

DESCRIPTION (provided by applicant): The oral and pharyngeal cavities making up the vocal tract undergo changes in size, shape, and relative proportions during the growth process from infancy through early childhood and adolescence. While acoustic theory indicates that vocal geometry is predictive of the spectrum shape of speech sounds, the relation between developmental changes in the vocal tract to changes in speech acoustics has not been adequately investigated. This is due to the scarcity of quantitative information on the anatomic remodeling of the vocal tract during development. To address this, we devised a magnetic resonance imaging (MRI) procedure to measure 36 predefined structures of the head and neck (Vorperian, et al., 1999) and secured an imaging database of 300 typically and 10 atypically (Trisomy 21) developing cases. This enabled us to construct a unique database of measurements on the concurrent development of the head, face and vocal tract structures. Our novel findings indicate that the development of vocal tract length follows a growth curve that is intermediate to the neural and somatic growth curves; that the relative contribution of the different vocal tract structures towards its lengthening changes during the course of development; and that the synchronous growth in hard and soft tissue structures persists during periods of accelerated growth. The proposed project combines imaging, acoustic analysis, and geometric modeling in an investigation of the development of the vocal tract from infancy through adulthood. The goals of this proposed research are to: (1) expand our measurement database by making additional linear and volumetric measurements, and supplement it with acoustic measurements representative of the specified vocal tract anatomy; (2) statistically model general trends in the individual and synchronous growth patterns of the vocal tract structures; (3) configure geometric models of the developing vocal tract and compute formant frequencies; and (4) correlate computed formant values with age specific acoustic data to make inferences regarding developmental patterns of articulator mobility. These goals will be addressed through our MR imaging database that spans the entire developmental period of typically and atypically developing cases, and a similar computerized tomography (CT) image database that will be secured. The findings will be of theoretical and clinical significance for an improved understanding of the anatomic correlates of speech development.