Mahr Tristan J, Rathouz Paul J, Hustad Katherine C
Waisman Center, University of Wisconsin-Madison.
Department of Population Health, Dell Medical School, University of Texas at Austin.
J Speech Lang Hear Res. 2025 Jan 2;68(1):79-90. doi: 10.1044/2024_JSLHR-24-00356. Epub 2024 Dec 16.
Earlier work has established developmental benchmarks for intelligibility and articulation rate, but the intersection of these two variables, especially within individual children, has received limited attention. This study examines the interaction between intelligibility and speaking rate in typically developing children between the ages 2;6 and 9;11 (years;months) and evaluates whether children show a speed-accuracy trade-off in their habitual speech production.
Speech samples of varying lengths were collected from 538 typically developing children. Intelligibility was measured as the number of words correctly transcribed by untrained adult listeners, and speaking rate was calculated in number of syllables per second. Regression models estimated the effects of age, utterance length, and speaking rate on intelligibility.
Intelligibility and speaking rate were positively correlated overall but weakly correlated after adjusting for age. In regression analyses, intelligibility increased with age and decreased with utterance length, and there was a trend for intelligibility to decrease with increased speaking rate, especially in longer utterances. At the individual level, for most children, there was a negative effect of speaking rate on intelligibility.
Our findings provide evidence from a large-scale sample for the hypothesis that children's speech is subject to a speed-accuracy trade-off where increased speaking rate leads to reduced articulatory accuracy and hence reduced intelligibility. Further research is needed on how to apply this trade-off in a clinical setting.
早期研究已确立了可懂度和发音速率的发展基准，但这两个变量的交叉情况，尤其是在个体儿童中的交叉情况，受到的关注有限。本研究考察了年龄在2岁6个月至9岁11个月之间的发育正常儿童的可懂度与说话速率之间的相互作用，并评估儿童在其习惯性言语产生中是否表现出速度-准确性权衡。
从538名发育正常的儿童中收集了不同长度的言语样本。可懂度通过未经训练的成年听众正确转录的单词数量来衡量，说话速率以每秒的音节数来计算。回归模型估计了年龄、话语长度和说话速率对可懂度的影响。
总体而言，可懂度与说话速率呈正相关，但在调整年龄后相关性较弱。在回归分析中，可懂度随年龄增长而增加，随话语长度增加而降低，并且存在可懂度随说话速率增加而降低的趋势，尤其是在较长话语中。在个体层面，对于大多数儿童来说，说话速率对可懂度有负面影响。
我们的研究结果从大规模样本中为以下假设提供了证据，即儿童的言语存在速度-准确性权衡，即说话速率增加会导致发音准确性降低，从而导致可懂度降低。关于如何在临床环境中应用这种权衡，还需要进一步研究。
