How to describe vowel sounds

Hi there! In this post you are going to learn a little more about vowel sounds.

Vowel sounds are pronounced with an open vocal tract so that there is no build-up of air pressure at any point above the glottis. This contrasts with consonants because there is a constriction or closure at some point along the vocal tract. A vowel is also understood to be syllabic: an equivalent open but non-syllabic sound is called a semivowel.

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 depending on the height (vertical dimension), backness (horizontal dimension) and roundedness (lip position).

The height is the vertical position of the tongue relative to either the roof of the mouth or the aperture of the jaw. In closed vowels, the tongue is positioned high in the mouth, whereas in open vowels, the tongue is positioned low in the mouth. The International Phonetic Alphabet identifies seven different vowel heights:

     - Close vowel (high vowel)

     - Near-close vowel

     - Close-mid vowel

     - Mid vowel

     - Open-mid vowel

     - Near-open vowel

     - Open vowel (low vowel)

The backness is the the position of the tongue during the articulation of a vowel relative to the back of the mouth. In front vowels, the tongue is positioned forward in the mouth, whereas in back vowels, the tongue is positioned towards the back of the mouth. The International Phonetic Alphabet identifies five different degrees of vowel backness:

      - Front vowel

      - Near front vowel

      - Central vowel

      - Near back vowel

      - Back vowel

The roundedness refers to whether the lips are rounded or not. In most languages, roundedness is a reinforcing feature of mid to high back vowels, and is not distinctive. Usually, the higher back vowel is the more intense rounded.

But these are not the only ones features, there are however still more possible features of vowel quality, such as the velum position (nasalization), type of vocal fold vibration (phonation), and tongue root position.

Nasalization refers to whether some of the air escapes through the nose. In nasal vowels, the velum is lowered, and some air travels through the nasal cavity as well as the mouth. An oral vowel is a vowel in which all air escapes through the mouth. 

Phonation describes whether the vocal cords are vibrating during the articulation of a vowel. Most languages only have voiced vowels, but several Native American languages contrast voiced and devoiced vowels. Vowels are devoiced in whispered speech.

And the last one, Tongue Root Retraction. The contrast between advanced and retracted tongue root resembles the tense/lax contrast acoustically, but they are articulated differently. Advance tongue root vowels involve noticeable tension in the vocal tract.

And that's it! If you have any doubt, please comment! ;)