Identifying Communicative Signals in Dysarthric Speech

描述（由申请人提供）：构音障碍，一种由大脑或外周神经损伤引起的言语障碍，导致言语运动缓慢、不精确和协调不良。对许多人来说，演讲不是一种可行的沟通方式。这对生活质量造成了毁灭性的后果。尽管有严重的构音障碍，许多人继续使用发声时，与熟悉的通信伙伴，这表明可靠的信息是嵌入在构音障碍的语音信号。识别这些一致的声音信号有可能为许多人提供另一种沟通渠道。以前的工作假设，显着的信息主要是编码在语音段。我们最近的研究表明，韵律特征，如基频（感知为音高），强度（感知为响度）和音节持续时间也携带重要的交际信息。我们假设，严重构音障碍的扬声器有足够的韵律控制，鉴于这些功能的变化在较低的时间尺度比段单位，如音素，因此可能更容易产生。我们已经展示了在孤立元音和短语中韵律的控制，以标记疑问句的对比。为了超越以前的工作，我们将研究一个更复杂的任务，更好地接近自然语音的韵律的本地音节级控制。15名有严重构音障碍的说话者和15名无障碍的对照者将产生四音节短语，重音放在指定的音节上以调节短语的含义。为了确定患有严重构音障碍的说话者是否能准确地发出压力信号，一组60名听众将判断每个录音中哪个音节被重读（具体目标1）。将进行统计分析，以检查每个扬声器的听众的准确性，并比较扬声器组的结果。为了了解构音障碍患者如何标记对比应力，我们将提取和分析几个声学特征，包括基频，强度，持续时间，停顿和频谱倾斜（具体目标2）。将对每个特征进行单独的方差分析，以量化其在信号压力中的重要性，并确定说话者之间的特征差异。最后，我们将比较严重构音障碍和非受损扬声器的压力模式，以更好地了解与构音障碍信号压力相关的声学相关性和补偿机制（具体目标3）。如果发音障碍的扬声器可以可靠地利用韵律线索，我们的研究结果将指导干预策略的发展，重点是韵律的作用，以提高自然沟通的有效性，并设计新颖的通信设备，利用韵律作为一种沟通信号。我们的最终目标是了解导致提高演讲者表达力的因素，并利用这些知识来帮助个人更自然，更有效地沟通，使他们能够更充分地参与教育，职业和社会活动。

DESCRIPTION (provided by applicant): Dysarthria, a speech disorder resulting from damage to the brain or peripheral nerves leads to slow, imprecise, and poorly coordinated speech movements. For many individuals, speech is not a viable communication option. This has devastating consequences on quality of life. Despite severe dysarthria, many individuals continue to use vocalizations when interacting with familiar communication partners suggesting that reliable information is embedded in the dysarthric speech signal. Identifying these consistent vocal signals has the potential to afford many individuals with an alternative channel of communication. Previous work has assumed that salient information is primarily encoded in speech sound segments. Our recent investigations have shown that prosodic features such as fundamental frequency (perceived as pitch), intensity (perceived as loudness), and syllable duration also carry significant communicative information. We hypothesize that speakers with severe dysarthria have sufficient control of prosody, given that these features vary over slower time scales than segmental units such as phonemes and thus may be easier to produce. We have demonstrated control of prosody in isolated vowels and in phrases to mark question-statement contrasts. To extend beyond previous work we will study a more complex task of local syllable-level control of prosody that better approximates natural speech. Fifteen speakers with severe dysarthria and fifteen non-impaired controls will produce four-syllable phrases with stress placed on specified syllables to modulate the meaning of the phrase. To determine whether speakers with severe dysarthria can accurately signal stress, a group of 60 listeners will judge which syllable was stressed in each recording (Specific Aim 1). Statistical analyses will be performed to examine listener accuracy for each speaker and to compare results across speaker groups. To understand how speakers with dysarthria mark contrastive stress, we will extract and analyze several acoustic features including fundamental frequency, intensity, duration, pause and spectral tilt (Specific Aim 2). Separate analyses of variance will performed on each feature to quantify its importance in signaling stress and to determine feature-wise differences between speakers. Last, we will compare stress patterning in speakers with severe dysarthria and non-impaired speakers to gain a better understanding of acoustic correlates and compensatory mechanisms associated with signaling stress in dysarthria (Specific Aim 3). If speakers with dysarthria can reliably exploit prosodic cues, our findings will guide the development of intervention strategies that focus on the role of prosody for improving the effectiveness of natural communication, and the design of novel communication devices that leverage prosody as a communicative signal. Our ultimate goal is to understand the factors that lead to improved speaker expressiveness, and to leverage this knowledge to help individuals communicate more naturally and effectively, enabling them to engage more fully in educational, vocational, and social activities.