English Vowels, Diphthong, and Triphthong
We begin the study of English sounds in this course by looking at vowels, and it is necessary to say something about the vowels in general before turning to the vowels of English.
Vowels are sounds made by voiced air passing through different mouth-shapes. The differences in the shape of the mouth are caused by different positions of the tongue and of the lips. In phonetics, a vowel is a sound in spoken language pronounced with an open vocal tract so that there is no build-up of air pressure at any point above the glottis, such as English ah! /ɑ:/ or oh! /oʊ/.
The articulatory features that distinguish different vowel sounds are said to determine the vowel's quality. Daniel Jones developed the cardinal vowel system to describe vowels in terms of the common features height (vertical dimension), backness (horizontal dimension) and roundedness (lip position).
Vowel height is named for the vertical position of the tongue relative to either the roof of the mouth or the aperture of the jaw.
* High Vowel : The tongue is positioned high in the mouth, such as /i/ and /u/.
* Low Vowel : The tongue is positioned low in the mouth, such as /a/.
The IPA prefers the terms close vowel /i/ and /u/ and open vowel /a/ and /æ/, respectively, which describes the jaw as being relatively open or closed.
Vowel backness is named for the position of the tongue during the articulation of a vowel relative to the back of the mouth.
* Front Vowel : The tongue is positioned forward in the mouth, such as /i/, /I/, and /æ/.
* Back Vowel : The tongue is positioned towards the back of the mouth, such as /u/, /a/, and /ɑ:/.
Roundedness refers to whether the lips are rounded or not. Although the lips can have many different shapes and position, at this stage, there are only three possibilities to be considered. These are:
* Rounded : The corners of...