PurposeThis study aimed to determine how tongue and jaw displacement changes impact acoustic vowel contrast in talkers with amyotrophic lateral sclerosis (ALS) and controls.MethodTen talkers with ALS and 14 controls participated in this study. Loud, clear, and slow speech cues were used to elicit tongue and jaw kinematic as well as acoustic changes. Speech kinematics was recorded using three-dimensional articulography. Independent tongue and jaw displacements were extracted during the diphthong /ai/ inkite. Acoustic distance between diphthong onset and offset in Formant 1–Formant 2 vowel space indexed acoustic vowel contrast.ResultsIn both groups, all three speech modifications elicited increases in jaw displacement (typical < slow < loud < clear). By contrast, only slow speech elicited significantly increased independent tongue displacement in the ALS group (typical = loud = clear < slow), whereas all three speech modifications elicited significantly increased independent tongue displacement in controls (typical < loud < clear = slow). Furthermore, acoustic vowel contrast significantly increased in response to clear and slow speech in the ALS group, whereas all three speech modifications elicited significant increases in acoustic vowel contrast in controls (typical < loud < slow < clear). Finally, only jaw displacements accounted for acoustic vowel contrast gains in the ALS group. In controls, however, independent tongue displacements accounted for increases in vowel acoustic contrast during loud and slow speech, whereas jaw and independent tongue displacements accounted equally for acoustic vowel contrast change during clear speech.ConclusionKinematic findings suggest that slow speech may be better suited to target independent tongue displacements in talkers with ALS than clear and loud speech. However, given that gains in acoustic vowel contrast were comparable for slow and clear speech cues in these talkers, future research is needed to determine potential differential impacts of slow and clear speech on perceptual measures, such as intelligibility. Finally, findings suggest that acoustic vowel contrast gains are predominantly jaw driven in talkers with ALS. Therefore, the acoustic and perceptual consequences of direct instructions of enhanced jaw movements should be compared to cued speech modification, such as clear and slow speech in these talkers.

中文翻译：

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肌萎缩侧索硬化症导致构音障碍的说话者的舌头和下巴特异性发音变化及其声学后果：响亮、清晰和缓慢言语的影响

目的本研究旨在确定患有肌萎缩侧索硬化症 (ALS) 的说话者和对照者的舌头和下颌位移变化如何影响声元音对比度。方法10 名患有 ALS 的说话者和 14 名对照者参与了这项研究。使用响亮、清晰和缓慢的语音提示来引发舌头和下巴的运动以及声音变化。使用三维发音记录仪记录言语运动学。在双元音 /ai/ 期间提取独立的舌头和下颌位移风筝。共振峰 1-共振峰 2 元音空间索引声学元音对比中双元音起始和偏移之间的声学​​距离。结果在两组中，所有三种言语改变都会引起下颌位移的增加（典型<缓慢<大声<清晰）。相比之下，在 ALS 组中，只有缓慢的言语才会引起独立舌头位移的显着增加（典型 = 响亮 = 清晰 < 慢），而所有三种言语修改都会引起对照组的独立舌头位移显着增加（典型 < 响亮 < 清晰 = 慢）。此外，ALS 组中的声元音对比度随着清晰和缓慢的语音而显着增加，而所有三种语音修改都会引起对照组中声元音对比度的显着增加（典型<响亮<慢<清晰）。最后，在 ALS 组中，只有下颌位移才导致声元音对比度增益。然而，在对照组中，独立的舌头位移导致大声和慢速语音期间元音声学对比度的增加，而下颌和独立舌头位移同样导致清晰语音期间元音声学对比度的变化。结论运动学研究结果表明，与清晰大声的讲话相比，缓慢的讲话可能更适合针对 ALS 患者的独立舌头位移。然而，考虑到这些说话者的缓慢而清晰的语音线索在声学元音对比度方面的增益是可比的，因此需要未来的研究来确定缓慢而清晰的语音对感知指标（例如可懂度）的潜在差异影响。最后，研究结果表明，患有 ALS 的说话者的声学元音对比度增益主要是由下颌驱动的。因此，增强下巴运动的直接指令的听觉和感知后果应与提示性言语修改进行比较，例如这些说话者的清晰而缓慢的言语。