Note to recorder:
It's my first time to use this.
Vowels are produced when the air flows out without being obstructed by
any part in the oral cavity. The shape of the oral cavity changes
when you move your jaw. It also changes when you move your tongue.
Generally, when the mouth is more open, the vowel has a lower tone;
when the mouth is more closed, the vowel has a higher tone. The number
of vowels in English is more than four times larger than that in
Japanese. Therefore, Japanese learners of English need to learn to
produce very many new vowels
Hello,
1 Recording is at natural speed and the other recording is at a slower speed. I hope it helps.