I have recently had a rather bizarre email correspondence with someone about his theory of vowels and consonants, from which belief I have been unable to shake him. The theory is that “vowels start with a fully closed, blocked glottis with the vocal folds pressed together. Consonants start with a non-closed glottis”. This, according to my correspondent, is what distinguishes the two classes of speech sound.
It is, of course, notoriously difficult to produce a watertight definition of vowel and consonant. If we leave aside the phonological definitions that have been advanced (that’s a different story), we are looking at the physical characteristics of the two sound classes. In Wikipedia’s article on Vowel, the lead paragraph gets off on the wrong foot: … a vowel is a sound pronounced with an open vocal tract, so that the tongue does not touch the lips, teeth, or roof of the mouth, such as the English "ah" /ɑː/ or "oh" /oʊ/. Most phonetics textbooks mention the fact that the tongue makes contact with the upper molar teeth in non-open vowels. Additionally, palatography has shown that the tongue makes contact with the outer edges of the palate in the case of front close and front close-mid vowels. There are clear illustrations of this in Daniel Jones’ Outline of English Phonetics (see Fig 37, p. 65 for /i:/), and he also gives palatograms for “short I” and /e/. Interestingly, he says that his English /u:/ does not produce a palatogram – I think that’s true for me too, but my Cardinal 7 and 8 certainly do have tongue-palate contact at the back of the palate.
· Nasal vowel / Oral vowel
· Previous Vowel / Later Vowel
· Rounded vowel / Unrounded vowel
· Open vowel / Close vowel
It seems a rather cut-price approach simply to list a few points with links to other articles. And goodness knows what the relevance of “Previous vowel/Later vowel” is. Some work is definitely needed here.