腦性麻痺說話者的國語聲調基本頻率(F0)型態與特性

The F0 Contour Pattern and Tone Characteristics of Mandarin Speakers with Cerebral Palsy

音調韻律的異常是腦性麻痺說話者常見的問題，他們的言語常被形容為緩慢、吃力、無節律以及音調無起伏等，而說國語患有腦性麻痺的說話者也常出現聲調方面的異常。在本研究的目的主要在於調查說國語的腦性麻痺說話者的單音節詞之聲調基本頻率(F0)型態與聲調特性，藉著與正常說話者的基頻資料比較，分析說國語的腦性麻痺者基頻走勢型態的偏異處，並比較三種不同腦性麻痺類型(痙攣型、徐動型及混合型)基頻走勢型態的差異。參與本研究者包括有三十位腦性麻痺說話者，其中十位具有徐動型特性，十位具有痙攣型特性，十位具有徐動加痙攣的混合型特性，此外還有十位無神經性疾病的正常說話者為研究的控制組。分析結果顯示腦麻說話者的平均基頻較正常說話者為高，音節時長較長。在基頻型態觀察方面，腦麻說話者基頻型態偏誤性較多，尤其在二、三聲的音節上，例如不管是在何種聲調，徐動型組的音尾常有一個下降調的型態，而痙攣型組的特性是基頻較無法降低，頻率變動的範圍較侷限。對腦性麻痺說話者而言，四種聲調中，第四聲問題最少，其次是一聲，而二、三聲最為困難，互相混淆的情況也最嚴重。腦麻說話者三、四聲基頻走勢的變化率較正常者為緩，走勢的變化率以痙攣組與混合型組最小。就整體而言，腦麻說話者基頻變化範圍並不小於正常者，但由於基頻走勢的變化率過小以及基頻走勢型態的偏異，造成腦麻說話者語音聲調上的異常。

Prosodic deviation is a common problem for CP speakers， whose speech is usually described as slow， labored， arhythmic and monotonous. The purposes of this study are to investigate the fundamental frequency (F0) contours of Mandarin dysarthic speakers with CP and F0 characteristics associated with tone production. The speakers included ten normal young adults and 30 young adults with CP of three types: athetoid， spastic and mixed. F0 patterns of the four basic tones for two sets of monosyllabic words were compared. Some acoustic variables associated with tone contours， including F0 slope， F0 range and syllable duration were compared among the four groups. The result shows that CP speakers had higher mean F0 and deviant F0 contour patterns， especially for tone 2 and tone 3. Instead of low tone pattern， the contour patterns of tone3 were very similar to those of tone 2. The salient characteristic associated with speakers in athetoid CP group is their tending to decrease F0 at the end of syllables regardless of the tone. The speakers in spastic CP group had more limited F0 range， and had greater difficulty in producing low pitch for tone 3. The acoustic analysis revealed that CP speakers had shallow F0 slope， longer syllable duration， and larger variation of F0 value across and within speakers. These findings are discussed in terms of the laryngeal control deficits associated with CP in tone production.