1. A cardinal vowel is a vowel sound produced when the tongue is in an extreme position, either front or back, high or low. 当舌头位于极端的位置，发出的元音就是定位元音，不论位置的前后或高低。
2. Different ways of complication or simplification from the five-vowel system might have resulted in the other types of vowel systems. 其他音系类型可能都是从五元音音系经历不同的过程演化而成的。
3. Secondly, we contrasted their vowel system and mainly investigated the influence of different parts of the initial consonant pronunciation on the evolution of the vowel system. 其次，对比了《广韵》与《潮语十五音》韵母系统，并重点考察了不同发音部位的声母片韵母演变所产生的影响。
4. It is in accordance with the vowel letters, vowel combinations of letters, consonants and consonant-letter acronym in the open and closed syllable syllable pronunciation of the law of memory. 它就是按照元音字母、元音字母组合、辅音字母及辅音字母组合在开音节和闭音节的读音规律记忆。
5. Sound pressure measurement, sound intensity measurement, sound power measurement, time field wave display, instantaneous sound power measurement and sound field indicator measurement. 声强测量、声压测量、声功率测量、时域示波、短/瞬时声功率测量和声场指示值测量。
