CONSTRAINTS AND STRATEGIES IN SPEECH PRODUCTION

这项研究的长期目标是帮助理解言语产生的运动控制，包括它的变异性、效率和交际效果。我们将建立在我们对声学目标、清晰度与努力的经济性、动态性能限制和声道建模以及新合作者的工作的初步发现的基础上。我们将根据以下假设通过实验提炼理论概述：(1)音素对比产生的分段控制机制是基于声学目标的。我们将研究在实现这些目标时的运动等效性。(2)声学目标部分取决于运动指令和发音动作之间以及发音和发音之间的饱和效应(非线性量子关系)。我们将在咬合块实验中研究饱和效应。(3)为了实现这些目标，言语运动被计划好，以便以最小的努力实现知觉对比。我们将考察不同语音条件下语音清晰度和发音能力的测量。(4)实现声学目标的编程必须利用运动指令和声学结果之间的关系的内部模型。我们将使用语音感觉运动适应范式来检验该内部模型的特性。(5)运动指令与声学结果之间的关系包括生物力学约束，我们用生理声道模型来研究生物力学约束。这项工作将包括：(A)进一步开发和使用说话人特定的声门上声道的生理/生物力学模型；(B)从几个说话人那里收集详细的声学、运动、力、肌电、磁共振和空气动力学数据，为模型的开发和验证以及生物力学饱和效应的定量探索提供基础；以及(C)进一步开发控制模型，并将其用于驱动生物力学模型，以测试关于声学目标、饱和效应、努力的经济性和动力学约束的假设。(6)感知和生产之间关系的性质及其对内部模型的完善程度可能因发言者而异。我们测量了说话人在语音识别中的敏锐度，并将这些测量与他们在语音运动学和声学方面的差异联系起来。在这些研究中，我们将使用我们的Emma运动换能器系统记录和分析下颌、唇部和舌部上各点的声学信号和运动；我们还将使用MRI收集解剖数据，并测量肌电、接触压力、气压和气流。我们还进行了几种感知实验，并将结果与生产实验的结果进行了比较。

The long-range goal of this research is to contribute to an understanding of the motor control of speech production, including its variability, efficiency and communicative effectiveness. We will build on our initial findings of acoustic goals, clarity versus economy of effort, kinetic performance limits and vocal-tract modeling, and on the work of new collaborators. We will refine a theoretical overview with experiments based on the following hypotheses: (1) Segmental control mechanisms for the production of phonemic contrasts are based on acoustical goals. We will examine motor equivalence in reaching those goals. (2) The acoustic goals are determined partly by saturation effects (non-linear quantal relations) between motor commands and articulatory movements and between articulation and sound. We will study saturation effects in a bite block experiment. (3) To achieve the goals, speech movements are planned so that perceptual contrast is achieved with minimal effort. We will examine measures of speech clarity and articulatory effort under varying speech conditions. (4) Programming to achieve acoustic goals must utilize an internal model of the relation between motor commands and acoustic results. We will examine properties of that internal model with a speech sensorimotor adaptation paradigm. (5) The relation between motor commands and acoustic results includes biomechanical constrains, which we study with physiological vocal-tract models. This work will include: (a) further development and use of speaker-specific physiological/biomechanical models of the supra-glottal vocal tract, (b) collection of detailed acoustic, movement, force, EMG, MRI and aerodynamic data from several speakers to provide bases for model development and validation and for quantitative exploration of biomechanical saturation effects, and (c) further development of control models and their use in driving the biomechanical models in tests of hypotheses about acoustic goals, saturation effects, economy of effort and dynamical constraints. (6) The nature of relations between perception and production and their degree of refinement of the internal model may differ across speakers. We measure speakers' acuity in speech discrimination and relate those measures to differences among them in speech kinematics and acoustics. In these studies we will record and analyze the acoustic signals and movements of points on the mandible, lips and tongue using our EMMA movement transducer system; we also gather anatomical data with MRI and we make measurements of EMG, contact pressures, air pressure and air flow. We also conduct several kinds of perceptual experiments and compare the results with those from the production experiments.