If we say that the difference between vowels and consonants is a difference in the way
that they are produced, there will inevitably be some cases of uncertainty or disagreement;
this is a problem that cannot be avoided. It is possible to establish two distinct groups of
sounds (vowels and consonants) in another way. Consider English words beginning with
the sound h; what sounds can come next after this h? We find that most of the sounds
we normally think of as vowels can follow (e.g. ein the word ‘hen’), but practically none
of the sounds we class as consonants, with the possible exception of jin a word such as
‘huge’ hjud. Now think of English words beginning with the two sounds bi; we find
many cases where a consonant can follow (e.g. din the word ‘bid’, or lin the word ‘bill’),
but practically no cases where a vowel may follow. What we are doing here is looking at
the different contexts and positions in which particular sounds can occur; this is the study
of the distributionof the sounds, and is of great importance in phonology. Study of the
sounds found at the beginning and end of English words has shown that two groups of
sounds with quite different patterns of distribution can be identified, and these two groups
are those of vowel and consonant. If we look at the vowel– consonant distinction in this
way, we must say that the most important difference between vowel and consonant is not
the way that they are made, but their different distributions. It is important to remember
that the distribution of vowels and consonants is different for each language.
We begin the study of English sounds in this course by looking at vowels, and it
is necessary to say something about vowels in general before turning to the vowels of
English. We need to know in what ways vowels differ from each other. The first matter to
consider is the shape and position of the tongue. It is usual to simplify the very complex
possibilities by describing just two things: firstly, the vertical distance between the upper
surface of the tongue and the palate and, secondly, the part of the tongue, between front
and back, which is raised highest. Let us look at some examples:
i) Make a vowel like the iin the English word ‘see’ and look in a mirror; if you tilt
your head back slightly you will be able to see that the tongue is held up close to
the roof of the mouth. Now make an vowel (as in the word ‘cat’) and notice
how the distance between the surface of the tongue and the roof of the mouth
is now much greater. The difference between i and is a difference of tongue
height, and we would describe i as a relatively closevowel and as a relatively
openvowel. Tongue height can be changed by moving the tongue up or down,
or moving the lower jaw up or down. Usually we use some combination of the
two sorts of movement, but when drawing side-of-the-head diagrams such as
Fig. 1 and Fig. 2 it is usually found simpler to illustrate tongue shapes for vowels
as if tongue height were altered by tongue movement alone, without any accompanying jaw movement. So we would illustrate the tongue height difference
between iand as in Fig. 3.