syllabic, vowels before l and r

1000-hours/sounds-of-english/15-mn.md

@@ -17,3 +17,8 @@
 > * *wrong idea* ⭢ `/rɔn aɪˈdiə/`
 > * *thinking of* ⭢ `/ˈθɪŋkɪn əv/`
 
+另外，`m`、`n` 常常会使之前的辅音，尤其是 `d`、`t` 变成**音节辅音**（*syllabic consonant*），比如，*didn't* `/ˈdɪd̩nt/`<span class="speak-word-inline" data-audio-uk="/audios/didn't-uk.mp3" data-audio-us="/audios/didn't-us.mp3"></span>, *wouldn't* `/ˈwʊd̩nt/`<span class="speak-word-inline" data-audio-uk="/audios/wouldn't-uk.mp3" data-audio-us="/audios/wouldn't-us.mp3"></span> —— 独自构成音节的那个辅音，例如这里的 `d`，下面多了个竖线作为标注，`d̩`。再比如，*rhythm* `/ˈrɪð̩m/`<span class="speak-word-inline" data-audio-uk="/audios/rhythm-uk.mp3" data-audio-us="/audios/rhythm-us.mp3"></span>。 
+
+有些词典会直接将 *didn't* 标注为 `/ˈdɪdənt/`，将 *wouldn't* 标注为 `/ˈwʊdənt/`，将 *rhythm* 标注成 `/ˈrɪðəm/`…… 但是，音节辅音内的元音音素，更准确地讲，更接近 `ɤ`（[2.2.1](13-pbmnfkgh)）而不是 `ə` —— 这个细微差异，竟然会使美国人轻易地听出外国口音[^1]。
+
+[^1]: *Manual of Amewrican English Pronuciation*, 4th edition, by Clifford H. Prator, Jr. Betty Wallace Robinett.