Aasland Wendi A, Baum Shari R, McFarland David H
School of Communication Sciences & Disorders, McGill University, Montreal, QC H3G 1A8, Canada.
J Acoust Soc Am. 2006 Apr;119(4):2372-81. doi: 10.1121/1.2173520.
Exploring the compensatory responses of the speech production system to perturbation has provided valuable insights into speech motor control. The present experiment was conducted to examine compensation for one such perturbation-a palatal perturbation in the production of the fricative /s/. Subjects wore a specially designed electropalatographic (EPG) appliance with a buildup of acrylic over the alveolar ridge as well as a normal EPG palate. In this way, compensatory tongue positioning could be assessed during a period of target specific and intense practice and compared to nonperturbed conditions. Electropalatographic, acoustic, and perceptual analyses of productions of /asa/ elicited from nine speakers over the course of a one-hour practice period were conducted. Acoustic and perceptual results confirmed earlier findings, which showed improvement in production with a thick artificial palate in place over the practice period; the EPG data showed overall increased maximum contact as well as increased medial and posterior contact for speakers with the thick palate in place, but little change over time. Negative aftereffects were observed in the productions with the thin palate, indicating recalibration of sensorimotor processes in the face of the oral-articulatory perturbation. Findings are discussed with regard to the nature of adaptive articulatory skills.
探索言语产生系统对扰动的代偿反应为言语运动控制提供了宝贵的见解。本实验旨在研究对一种这样的扰动——摩擦音/s/产生过程中的腭部扰动——的代偿情况。受试者佩戴了一种特别设计的电子腭位仪（EPG）装置，该装置在牙槽嵴上有一层丙烯酸堆积物，还有一个正常的EPG腭板。通过这种方式，可以在一段针对特定目标的强化练习期间评估代偿性舌位，并与未受扰动的情况进行比较。对九名说话者在一小时练习期间发出的/asa/进行了电子腭位、声学和感知分析。声学和感知结果证实了早期的研究发现，即在练习期间，佩戴厚人工腭时发音有所改善；EPG数据显示，佩戴厚腭板的说话者总体上最大接触增加，中间和后部接触也增加，但随时间变化不大。在佩戴薄腭板的发音中观察到了负面后效，表明在面对口腔发音扰动时感觉运动过程的重新校准。针对适应性发音技能的性质对研究结果进行了讨论。
