“vowel: Speech sound in which air from the lungs passes through the mouth with minimal obstruction and without audible friction like the f in fit. The word also refers to a letter representing such a sound (a, e, i, o, u, and sometimes y). In articulatory phonetics (see articulation), vowels are classified by tongue and lip position; for example, high vowels like the i in machine and the u in flute are both pronounced with the tongue arched high in the mouth, but in u the lips are also rounded. Single vowel sounds are monophthongs; two vowel sounds pronounced as one syllable, like the ou in round, are diphthongs.”
Excerpted/Adapted from: Stevens, Mark A., Ed. Merriam-Webster’s Collegiate Encyclopedia. Springfield, Massachusetts: Merriam-Webster, 2000.
Mark's Text Terminal 