Tjaden K, Turner G
Department of Communicative Disorders and Sciences, State University of New York at Buffalo, 14214-3005, USA.
J Speech Lang Hear Res. 2000 Jun;43(3):683-96. doi: 10.1044/jslhr.4303.683.
This study describes segmental timing patterns for a passage read by speakers with ALS and a group of age- and gender-matched neurologically healthy speakers. Segment durations for ALS speakers' habitual rates (ALS condition) were compared to segment durations for healthy speakers' habitual and slow reading rates (Control Habitual and Control Slow conditions). Temporal differences for pairs of sound classes (i.e., long-short vowels, voiceless-voiced fricatives, voiceless-voiced stop gaps, high-low vowels) and prepausal lengthening of vowels also were studied. The results of the ALS-Control Habitual comparison suggested that the slowed articulatory rate of ALS influences segmental timing for most phonetic events. The finding that local segmental cues for disordered speakers were broadly consistent with their overall (slow) articulatory rate suggests that duration likely does not contribute in a significant way to intelligibility deficits in ALS. A qualitative analysis further indicated that the slowed rate of ALS is not uniformly distributed across phonetic events, but influences segment durations of particular sound categories in ways consistent with the disease process. The analysis comparing segment durations for the ALS and Control Slow conditions suggested that the overall pattern of segmental timing for speakers with ALS was broadly similar to the pattern for voluntarily slowed speech of healthy talkers. Finally, temporal differences for sound classes (i.e., voiceless-voiced fricatives, long-short vowels) and prepausal lengthening for speakers with ALS typically were similar to healthy speakers' habitual and slow speech. There were substantial variability within speaker groups and reversals of expected effects, however. The implication is that temporal differences for sound classes, such as short and long vowels, are not a particularly reliable perceptual cue for listeners.
本研究描述了肌萎缩侧索硬化症（ALS）患者以及一组年龄和性别匹配的神经功能正常的说话者朗读一段文章时的分段计时模式。将ALS患者的习惯语速（ALS条件）下的片段时长与健康说话者的习惯语速和慢速朗读语速（对照习惯和对照慢速条件）下的片段时长进行比较。还研究了成对音类（即长短元音、清浊擦音、清浊塞音间隙、高低元音）的时间差异以及元音的句前延长。ALS与对照习惯的比较结果表明，ALS患者减慢的发音速度会影响大多数语音事件的分段计时。无序说话者的局部分段线索与其总体（较慢）发音速度大致一致这一发现表明，时长可能对ALS患者的可懂度缺陷没有显著影响。定性分析进一步表明，ALS患者减慢的语速并非均匀分布于所有语音事件中，而是以与疾病进程一致的方式影响特定音类的片段时长。ALS与对照慢速条件下片段时长的比较分析表明，ALS患者的分段计时总体模式与健康说话者自愿放慢语速时的模式大致相似。最后，ALS患者音类（即清浊擦音、长短元音）的时间差异和句前延长通常与健康说话者的习惯语速和慢速语音相似。然而，说话者组内存在很大差异，且预期效果出现了反转。这意味着，诸如长短元音等音类的时间差异对听众来说并不是特别可靠的感知线索。
