A vowel is a sound produced with vibration of the vocal folds, and
without audible friction in the vocal tract. Thus all vowels are voiced,
as they are produced with vibration. Consonants are sounds that are
produced with at least partial obstruction of the vocal tract, and may
be produced with or without vibration of the vocal folds. Thus,
consonants are both voiced and voiceless. A consonant combines with a
vowel to form a syllable in speech. The vowel is always the nucleus of
the syllable.
