Letters vs. Sounds Vowels and Consonantsare the letters of the alphabet that we write. Vowels: a, e, i, o, uConsonants: all letters except a, e, i, o, u Vowel Sounds and Consonant Soundsrepresent pronunciation.Prator & RobinettManual of American English Pronunciation Related Lessons: Vowel SoundsConsonant SoundsHow do I know if a sound is voiceless or voiced? Tell your friends. Share this lesson.