本研究提出了語音證據，解釋國語音節尾鼻音之變化。雖然三位語音評審一致認為台灣國語裡，韻腳/iŋ/ (ㄧㄥ) 產生了轉變，但他們卻持不同看法；其中兩位認為尾音變成/in/ (ㄧㄣ)，而另外一位則主張軟顎鼻音(ㄥ)因為前面的母音鼻音化而消失。為了解決這樣的歧見，這篇研究分析/in/, /iŋ/, /i/ 和/ /的語音屬性。結果顯示，台灣受試者並未去除尾鼻音而把母音鼻音化，倒是傾向將尾鼻音轉變成齒鼻音(ㄣ)。最後，這項研究討論國語的尾鼻音轉換，對中國方言語音變化的意涵。

This paper presents phonetic evidence to resolve the transcription disagreement concerning the syllable-final nasal shift in the variety of Mandarin spoken in Taiwan. In the word reading experiment, three judges agreed that the rhyme /iŋ/undergoes a sound change, but they perceived the nasal coda shift differently.Two of them transcribed it as a modification from /iŋ/ to /in/, whereas the other asserted that the velar nasal disappears with its preceding vowel nasalized. In order to resolve this transcription conflict, this study analyzes the acoustic attributes of the speculative sound alterations in question,including /in/, /iŋ/, /i/
and / /. The phonetic analysis indicates that the Taiwanese participants do not nasalize the preceding vowel deleting the nasal coda but they tend to pronounce the post-vocalic velar nasal as its dental counterpart. This study concludes by discussing the implications of the synchronicvariation for the theories of the nasal coda shift in Chinese dialects.