Closing diphthong闭二合元音
improper diphthong非正式的双母音;双母音
falling diphthong降二合元音
Narrow diphthong窄二合元音
rising diphthong上升二合元音;上升双母音
centring diphthong中向双元音;央二合元音
Wide diphthong宽二合元音
diphthong nucleus二合元音的核心
a diphthong双元音
/as diphthong, but this phenomena died away from the younger group.
/发音成双元音“(?)” ,但在青年层这种现象已经消失了。
参考来源 - 吉林省汪清县地区方言研究N-COUNT（可数名词） A diphthong is a vowel in which the speaker's tongue changes position while it is being pronounced, so that the vowel sounds like a combination of two other vowels. The vowel sound in "tail" is a diphthong. 双元音