延長言語時長與刻意停頓對痙攣型腦性麻痺兒童言語清晰度的影響

Effect of Prolonged Speech and Deliberate Pauses on the Speech Intelligibility of Adolescents with Spastic Cerebral Palsy

本研究探討延長言語時長和刻意停頓訓練方案介入對痙攣型腦性麻痺兒童言語清晰度與言語自然度的影響。採前後測實驗設計，實驗組為十六位痙攣型腦性麻痺兒童，接受延長言語時長和刻意停頓訓練方案；另外十四位痙攣型腦性麻痺兒童為對照組，接受互動式語文訓練方案。分別於訓練前、訓練結束後三天內、訓練結束三週後收錄受試者的語言樣本，進行聽知覺評估與聲學分析，以了解延長言語時長和刻意停頓訓練的介入效果與短期保留效果。研究結果顯示：一、延長言語時長和刻意停頓訓練的介入有效提升腦性麻痺兒童言語清晰度，且提升效果顯著優於互動式語文訓練方案；此外，亦可降低說話速度，且其音節時長、停頓時長與停頓數量隨之增加，但言語自然度則會受影響而略為降低；對照組前後測言語清晰度與自然度的表現雖達顯著差異，但清晰度進步幅度有限。經共變數分析結果顯示，實驗組提升言語清晰度、放慢說話速度的效果皆較控制組佳。二、經三週的追蹤，實驗組在言語清晰度、說話速度及時間性聲學特徵仍持續保留介入效果；對照組的言語清晰度同樣有保留介入效果。經共變數分析，實驗組在維持期的言語清晰度表現顯著地優於控制組。綜合來看，雖然延長言語時長和刻意停頓訓練會使受試者言語自然度受到影響而稍有降低，但此訓練方案卻可有效且明顯的提升腦性麻痺兒童的言語清晰度。本研究針對此訓練方案對腦性麻痺兒童言語清晰度與言語自然度的可能影響原因加以討論，並對未來語言治療介入與研究提出建議。

Purpose: This study explores the effect of prolonged speech and deliberate pause training on the speech intelligibility and naturalness of adolescents with spastic cerebral palsy.
Methods: For the sample, we selected 16 adolescents (10 boys, 6 girls) with spastic cerebral palsy, who had received 8 sessions of prolonged speech and deliberate pause training. An additional 14 adolescents (9 boys, 5 girls) with spastic cerebral palsy, who had participated in the interactive language program, were recruited for the control group. Before and after the interventions, the participants' speech samples (including nine 6- to 12-word sentences and one short essay of 71 words) were collected using the same procedure to assess their speech intelligibility, speech naturalness, speaking rate, and temporal acoustic features (i.e., syllable duration, pause duration, and pause frequency). Changes between the pre- and post-training phases were measured to evaluate the training effects.
Results/Findings: The results showed that (1) the prolonged speech and deliberate pause training was effective for improving the participants' speech intelligibility, reducing their speaking rate, lengthening their syllable duration, and increasing their pause duration and frequency. However, we observed that a few participants' speech naturalness decreased after undergoing the training. Although the control group experienced significant differences regarding speech intelligibility and naturalness, the effects of the interactive language program for increasing speech intelligibility were limited. Based on the analysis of covariance (ANCOVA) results, the post-training performances of the experimental group differed significantly from those of the control group. This shows that the effect of the training for improving speech intelligibility was greater in the experimental groups than in the control group. (2) After 3 weeks of follow-up session, the effects of the prolonged speech and deliberate pause training on the participants' speech intelligibility and speaking rate were maintained. The speech intelligibility of control group was also maintained. According to the ANCOVA results, during the maintenance period, the speech intelligibility of the experimental group was significantly superior to that of the control group.
Conclusions/Implications: The results of this study indicate that prolonged speech and deliberate pause training can improve the speech intelligibility of speakers with spastic cerebral palsy in clinical settings. A slight reduction in speech naturalness may be an acceptable sacrifice for a significant improvement in speech intelligibility. The effect of the interactive language program on speech intelligibility and naturalness among speakers with cerebral palsy still requires further investigation. Future studies can emphasize identifying slowing speaking rates that are effective for increasing speech intelligibility while simultaneously retaining naturalness. Finally, this study presents a discussion on the effect of this training program for improving speech intelligibility and presents suggestions for future speech training program designs.