本研究主要以前後測的教學實驗設計，探討調整說話速度訓練方案的介入對痙攣型腦性麻痺者在提升說話清晰度、擴大元音構音空間及降低說話速度的效果。受試者為為十六名痙攣型腦性麻痺者，參與六週的調整說話速度訓練方案。方案介入前後，受試者分別進行介入前、介入後及維持期等共三次的語詞及短文說話樣本的收錄，以瞭解此訓練方案的介入及維持效果。研究結果顯示，調整說話速度訓練方案可提升痙攣型腦麻者的說話清晰度、擴展元音構音空間及增加元音時長，但短文說話速度無則顯著差異；經兩週的追蹤，受試者在說話清晰度及元音構音空間仍持續保留介入效果，但元音時長和短文說話速度則無保留介入效果。就變項間的關係而言，不論在前測和後測階段，元音構音空間大小對短文清晰度得分皆有顯著的迴歸解釋力，分別為32.7%及68.4%；在後測階段，元音構音空間的改變量對短文清晰度得分改變量的預測力為67.3%，顯示說話者元音構音空間大小可作為說話清晰度的指標外，且介入後所產生的元音構音空間改變量亦可作為說話清晰度介入成效的參考依據。本研究結果可以作為語言治療師及特教老師為腦性麻痺者擬定相關語言治療計畫及活動設計的參考。

The purpose of this study was to explore the effects of the speaking-rate training program on speech intelligibility for 16 students with spastic cerebral palsy. All participants received the speaking-rate training program for six 45-minute sessions. Before and after the intervention of speech training programs, individual subjects' speech intelligibility, vowel working-space and speaking rate were measured to evaluate the effects of training. The results showed that the speaking-rate training program was effective in improving speech intelligibility, expanding vowel working- space areas, and decreasing speaking rate. Over a two-week tracking period, the effects of this program on speech intelligibility and vowel working-space were maintained. Furthermore, individual subjects' vowel working-space was found to positively correlate with their speech intelligibility, and it could account for 67.3% of the improvement in speech intelligibility after the intervention. These results suggest that speakers with spastic cerebral palsy can benefit from the speaking-rate intervention program, and furthermore that vowel working-space area could be an important component of global estimates of speech intelligibility. The improvement of vowel working-space after the training program can be taken as a measure of the positive impact of training on speech intelligibility.