VOWEL definition: 1. a speech sound produced by humans when the breath flows out through the mouth without being…. Learn more. The vowels of English are A, E, I, O, U, and sometimes Y. Learn how they’re used, the difference between short and long vowels, and how Y relates to vowels. Vowel definition: A vowel is a sound produced with a comparatively open configuration of the vocal tract. In everyday language, a vowel is a letter (sound) of the English alphabet that is not a consonant. Contents What are vowel sounds? Categories of the vowel sounds Why is vowel sounds hard to pronounce? Short vowels in the IPA Long vowels in the IPA Diphthong vowels (double) in the IPA What are vowel sounds? English has fifteen vowel sounds represented by the letters a, e, i, o, and u. The letters y, w, and gh are also commonly used in vowel sound-spellings. Vowel sounds are produced with a relatively open vocal tract. Consonant sounds, in contrast, are created by pushing air through a ...