Even though you might know some of the following curiosities - either by unconscious knowledge or by previous studying - I bet you don’t know most of them. From phonology to prosody, history to linguistics, you get vowels everywhere. Their essence is to structure segments… consequently, they structure the speech. This is why those complex, diverse sounds end up being forgotten, precisely due to their productivity. Let’s check some curiosities of English vowel sounds...
First, English idiom is stress-timed. In other words, its rhythmic impression relies on symmetric timing of stress points, not segments. Consequently, it is simpler to omit or to reduce some phonemes to speed up speech. Frequently, the reduced sound in different words is the vowel, for it is more flexible, sensitive to context shifts.
Secondly, we identify vowels by its tone: “stressed” or “unstressed” vowel sounds. Their description includes those terms.
OK… so, which “vowel” letter is missing in this text?