INTRODUCTION
In the previous module, you learned about English consonants. Among other things, we mentioned some crucial reasons for starting with the description of consonants. We stated that consonants play a more significant role in making English understood than vowels. Additionally, we emphasized that consonants are generally formed by a specific and definite interference of the vocal organs with the air stream, making them easier to describe and understand. In this module, we will delve into English vowels, understanding that like consonants, vowels are sounds, and the principle underlying their production is the same as that of consonants.
Interestingly, vowels pose more difficulty in description due to the absence of physical articulators, except for the tongue, to describe their production. Nonetheless, there are basic principles guiding vowel production.
OBJECTIVES
By the end of this unit, you should be able to:
- Explain the parameters used in classifying English vowels.
- Correctly identify English vowels from the sound inventory.
MAIN CONTENT
Parameters
According to Elugbe (2000), the quality of a given vowel sound depends on the shape of the vocal tract, as determined by the tongue, lips, and the soft palate, which controls the velic passage.
Contrary to consonant classification, which uses Voicing, Place of Articulation, and Manner of Articulation, vowel classification differs in two key ways:
- The tongue does not make direct contact with the roof of the mouth or oral cavity during vowel production.
- All vowels are naturally voiced due to vocal cord vibration.
These differences render the classification of voicing, place, and manner of articulation redundant for vowels. Vowels are classified based on four parameters: Tongue Height (vertical), Tongue Horizontal Position, Shape of the Lips, and Vowel Length, discussed in detail below.
Tongue Height (Vertical)
This refers to the height or depth of the tongue in the oral cavity, indicating the distance between the upper surface of the tongue and the palate. Refer to Diagram 1 below:
From the given diagram, we observe the following:
- When the front of the tongue is flat on the bottom of the mouth, and the distance between the upper surface of the tongue and palate is open, the vowel /a:/ (as in 'star') is produced.
- Raising the front part of the tongue slightly, with an open distance between the tongue and the palate, results in the vowel /æ/ (as in 'pat').
- Keeping the mouth wide open and raising the front higher again, with a closer distance between the tongue and the palate (close mid), produces vowels like /e/ (as in 'met').
- Raising the front part of the tongue to a very high position, hidden behind the teeth, with a close distance between the tongue and the palate, produces /i:/ (as in 'sea').
It's important to note that with each vowel, the tongue is raised slightly higher than the previous position until it reaches the highest position.
Tongue Position (Horizontal)
This describes how forward or backward the tongue is positioned. For example, the front part of the tongue is involved in the production of front vowels /i:/, /ɪ/, /e/, and /æ/. The back of the tongue is correspondingly used in the production of back vowels /a:/, /o:/, /o/, /u/, /u:/. Refer to Diagram 2 below:
To experience this concept:
- Move the back of your tongue very close to the soft palate, drawing air inward to produce the vowel /u:/; observe the difference in the high front and high back position of the tongue.
- Lower the back of the tongue slightly from /u:/ to produce /u/ (as in 'put').
- Lower the back of the tongue a bit more for /É”:/ (as in 'fought').
- Further lower the back of the tongue for /É”/ (as in 'pot').
Did you notice any changes in the tongue's position during the production of these words?
Tongue Position Observation
Did you notice any changes in the position of the tongue during the production of these words?
At this point, it is essential to quickly recap what we have covered. We've established that tongue 'height' and 'frontness' are crucial aspects of vowel classification. You can organize vowels in a grid based on these two dimensions. The bottom of the grid is typically drawn shorter because there is limited room for the tongue to maneuver as the mouth opens wider. To experience these distinctions, pronounce the words under Diagram 2 and note the position of your tongue and its proximity to the roof of the mouth.
Lip Rounding
This pertains to the shape of the lips in producing certain vowels. During the production of any vowel, the lips may be pushed forward into a round shape or drawn backward into a spread and flat (closed) shape. Alternatively, the lips may remain neutral. Try the following:
- Say a long /i:/ as in 'pee' [iiiii].
- Now say a long /u:/ as in 'you' [uuuuu].
Did you observe the changes in the shape of the lips? A careful study of your lips in front of a mirror will reveal that the lips are spread when saying [i:] and rounded when saying [u:]. Interestingly, when saying [æ] as in 'back' or 'mat,' the lips are neither spread nor rounded.
Duration (Vowel Length and Quality)
This concerns the time spent during the production of certain vowels in comparison to others and the muscular activity involved. In English, there are short vowels and long ones, denoted by adding a colon after the vowel, e.g., /i:, a:, u:/. Refer to the tables showing short and long English vowels from the International Phonetic Association (IPA).
Many English speakers often mistake the distinction between short and long vowels.
Length of Vowels
Now say the words in the various boxes in the tables out loud. Did you notice any difference in the length of the vowels?
Indeed, in each box in the tables of vowels, two differences exist:
- There is a difference in quality, where the tongue position is higher and more directed to the edges of the vowel area for the long vowels than for the short ones.
- There is also a length difference, also known as a difference in quantity. The way the vowels are written in the examples above demonstrates differences in both quality and quantity. Note that quantity and length refer to duration. Hence, it takes longer to produce the vowel [u:] than [ɪ] in words.
It's essential to remember that duration refers to the time it takes to produce a vowel, while quality refers to the way the vowel sounds in our ears.
SELF ASSESSMENT EXERCISE
Now try to find more examples to exemplify pairs of similar but different vowels based on 'duration' and 'quality.'
CONCLUSION
Describing vowels is more challenging than describing consonants because within the bounds of the 'vowel-space' (generally around the palatal region), there are literally infinite possible vowels, and each person's vowels differ. This implies that a general description of a vowel is more of an approximation than an exact description. Parameters for describing vowels, such as tongue position, lip shape, and duration, exist, just as they do for consonants.
SUMMARY
In this unit, we aimed to familiarize you with the various parameters used for the classification of English vowels. We explained how the tongue position can be manipulated vertically and horizontally. Additionally, we explored how lip rounding (shape of the lips) and vowel duration serve as relevant parameters for classifying vowels. Clearly, the parameters for describing vowels differ from those used for consonants.
Leave a comment behind