Articulatory Characteristics of Speakers with Motor Speech Disorder

本研究试图利用来自X射线微束语音产生数据库的X射线微束数据和患有AOS的说话者的X射线微束数据来描述患有言语失用(以下简称AOS)的说话者的发音特征。本研究的特点是多个说话者的标准数据，这些数据能够估计正常发音的范围，并使用三种不同的语速来描述语速对发音的影响，并在可比较的语速中比较两组之间的差异。由于其坐标无关的性质，采用了基于咬合架速度的参数。对于下唇和下颌，计算了每一次重复的速度峰个数、平均峰值速度、主峰速度、平均主峰速度和总行走距离，发现语速对速度峰值个数和平均峰值速度有影响，而主峰个数和平均主峰速度与语速无关，提示后两个参数可能与发音的语音内容有关。我们的初步分析显示，主要的语速峰值出现在发音中特定的时间位置，这为利用这些峰值描述发音时间提供了可能性。在所考察的大多数参数中，AOS说话者的表现与正常说话者相当，这突显了在描述语音障碍的发音特征时考虑语速的影响的重要性。

The present study attempted to develop descriptions of articulatory characteristics of speakers with apraxia of speech (hereafter AOS), a motor speech disorder, using X-ray microbeam data from the X-ray microbeam speech production database (hereafter XRMB-SPD) and of speakers with AOS. The present study is characterized by multi-speaker normative data that enabled estimation of range of normal articulation and the use of three different speaking rates that afforded description of the effect of speaking rate on articulation and comparison between the two groups in comparable speech rate. Parameters based on articulator speed were employed because of their coordinate-independent nature. For the lower lip and the jaw, number of speed peaks, mean peak speed, number of major speed peaks, mean major peak speed, and total distance travelled, were calculated for each repetition.Effects of speech rate were observed in the number of speed peaks and mean peak speed, while the number of major speed peaks and mean major peak speed appeared to be independent of speech rate, suggesting that the latter two parameters may be related to the phonetic content of utterance. Our preliminary analysis revealed that major speed peaks appeared in particular temporal locations in the utterance, opening the possibility of describing articulatory timing using these peaks. The performances of the AOS speakers were found to be comparable with those of normal speakers speaking slowly, for most of the parameters examined, highlighting the importance of accounting for the effect of speech rate in the description of articulatory characteristics of disordered speech.