The student was practising making a new vowel sound.

这个学生正在练习发一个新的元音。

youdao

For example, in many languages the vowel sound "I" is associated with smallness-little, tiny, petit, nino, and so on-whereas the sound "a" or "o" is associated with largeness-grand, gross, gordo, etc.

举例来说，在许多语言中，元音“i”与小相联系，如little, tiny, petit, nino等等——反之，元音“a”，“o”与大有关，如grand, gross, gordo等等。

youdao

Where, by leaving out a Vowel to save a Syllable, we form so jarring a Sound, and so difficult to utter, that I have often wondred how it could ever obtain.

通过去一个原音省了一个音节，我们创造了这种非常难听并且难发的语音，让我怀疑这样的语言是怎么存在下来。

youdao

The whistled language replaces each vowel or consonant with a whistling sound: two distinct whistles replace the five Spanish vowels, and there are four whistles for consonants.

UNESCO: Culture