本論文為以共振峰頻率資料來研究台灣華語母音音質之聲學研究。 本研究的受試者為六名生長在台灣台北市的男性華語母語使用者。本研究使用的測試字為70個包含所有韻母型態的單音節字。語音資料是利用KAY CSL 4100 (KAY Electronics)來錄製及分析。本研究所採用的資料為獨立發音且無聲母的測試字。 根據共振峰頻率資料本研究得到以下有關台灣華語母音音質的發現。首先研究的部分為音標所隱含的語音對比。在齒槽（alveolar）及後齒槽（post-alveolar）組的舌尖母音（apical vowels）間並沒有發現音質上的顯著差別，但統計及其它證據支持低母音裡的前後對比及中母音裡的半開（open-mid）及半閉（closed-mid）對比的存在。 其次，研究的結果也包括語音環境中的音段對於母音音質的影響。結果發現韻母中的元素，包含母音前介音、母音後介音、及韻尾鼻音，都對母音有不同的語音制約（conditioning）。另外，本研究發現順同化（progressive assimilation）比逆同化（regressive assimilation）對於低母音音質有較大的影響。 第三，本研究藉由與之前聲學研究的結果作比較來討論台灣母音音質的改變。結果發現硬顎及後硬顎組的舌尖母音間的音質差異隨著時間縮小終至於消失。此外，研究發現半閉母音及半開母音在母音高度及母音前後相對位置出現反轉。共振峰頻率的比較顯示這種反轉的原因為半閉母音[e]在音質上的改變。然而，我們需要進一步的研究才能對這些音質的改變有合理的解釋。 最後，本研究以共振峰頻率的形式描述及紀錄了當代台灣華語表層母音的音質。希望這些資料能對台灣華語母音的研究有所貢獻。 / This thesis is an acoustic study that investigates the vowel quality of Taiwan Mandarin vowels with formant frequency data. The subjects of this study included six male native Mandarin speakers born and raised in Taipei city, Taiwan. Testing items used in this study were 70 syllables that involve all combinations of segment in the syllable final. The speech data were recorded and analyzed with KAY CSL 4100 (KAY Electronics). The data discussed in this study were testing items produced in citation form without initial consonant. The vowel qualities of Taiwan Mandarin surface vowel were measured and analyzed. Several results concerning the vowel quality of Taiwan Mandarin surface vowel phones were reported based on the formant frequency data. Firstly, the distinction between vowel phones implied by their transcription was examined. The difference in vowel quality was not observed in the alveolar and post-alveolar groups of apical vowels, while the front-back distinction in low vowels and the open-mid and closed-mid distinction in mid vowels were found with statistic and other evidence. Secondly, the conditioning of segments in the neighboring environments on the vowel quality was investigated. It is found that elements in the syllable final, including pre-nuclear, post-nuclear glide and coda nasals, generally have different types of conditioning on the vowel. In addition, the progressive assimilation was found have greater influence on the vowel quality of low vowel phones than the regressive assimilation. Thirdly, the change in vowel quality was discussed through the comparison with results in previous acoustic studies. The difference in vowel backness between the alveolar and post-alveolar groups of apical vowels were found to be decreasing and eventually disappeared. Besides, the relative vowel height and backness of closed-mid and open-mid vowel were found to be in reverse compared with that in the literature. Comparison in formant frequencies showed that this reverse lay in the change of vowel quality in the close-mid [e]. However, further investigations were needed to offer reasonable explanations for the change. Finally, the vowel qualities of present Taiwan Mandarin surface vowel phones were described and recorded as the formant frequency data presented in this study. Hopefully, the data could contribute to the study of vowels in Taiwan Mandarin.