What is produced by combining two vowels into a single syllable?

Combining two vowels into a single syllable results in a diphthong. A diphthong is a complex vowel sound that begins with one vowel sound and glides into another within the same syllable. This blending produces a sound that is distinct from either vowel sound when pronounced individually, creating a unified phonetic experience.

For example, in words like "coin" or "out," the vowel combinations create a smooth transition between the two sounds, which is characteristic of diphthongs. Understanding diphthongs is important in phonetics and pronunciation, as they play a key role in the rhythm and sound of spoken language.