Allophones

Anyone working on an unwritten language must not only make a list of the phonemes of that language. They must also discover their vari­ant forms or allophones. In fact, an essential part of the phoneme identification process consists of finding out which variant sounds 'belong' to each phoneme. The amount of variation differs from phoneme to phoneme. For

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example, the very slight alterations in the pronunciation of English /s/ are mostly imperceptible and unimportant, whereas the variants of English /1/ are noticeable even to the untrained ear.

Sometimes the variation is random: no two sounds can ever be exactly the same, no matter how hard a speaker tries to replicate one. These slight differences normally pass unnoticed. When sounds vary randomly in this way, they are said to be in free variation.

At other times, the variation is predictable. The way a phoneme is pronounced can be conditioned by the sounds round it, or by its posi­tion in the word. Take the English phoneme /p/. When it occurs at the beginning of a word, it is pronounced with aspiration (a puff of breath). After /s/, this puff of breath disappears. This can be tested by holding a sheet of paper in front of the mouth and saying the words spot, spill, pot, pill. In the case of spot and spill, the paper remains motionless. But when pot and pill are pronounced, the accompanying puff of breath makes the paper billow out. In short, the aspirated vari­ant [p^h] and the unaspirated one [p] are both allophones of the phoneme /p/, and each occurs in a different and predictable set of environments. In linguistic terminology, they are in complementary distribution, since one set of environments complements the other.

A neat and currently fashionable way to express this is to take one variant as more basic than the other(s), and to state the circum­stances under which any change in the basic form occurs. If we regard [p] as basic, we can then say that [p] changes into [p^h] at the beginning of a word. This can be stated briefly as follows:

Fig. 9

Or, to take another example, consider the English phoneme /I/. This has one format the beginning of a word, and another form at the end. In a word such as lip, the first consonant is a 'clear' l. pronounced by placing the tip of the tongue just behind the teeth and keeping the back of the tongue fairly low. In pill, the tongue tip is in the same

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place, but the back of the tongue is raised, resulting in a 'dark⁴ /. So the 'clear' variant [1] and the 'dark' variant ) are both allophones of the phoneme /1/. If we regard [1] as basic, we can say that [1] changes to (4) at the end of a word:

l-> / –––––– #. That is:

Fig. 10

(The distribution of these allophones is in fact more complex than the above paragraph suggests. For further information, see the books recommended on page 205).

Sound combinations

In addition to identifying and analysing the phonemes of a language, a linguist must also work out ways in which the phonemes may be com­bined. Every language has certain permitted sequences of sounds, and others which are not allowed.

In English, for example, a word which begins with three consonant-type phonemes always obeys three strict rules:

1. The first phoneme must be /s/.

2. The second phoneme must be /p/ or /t/ or /k/.

3. The third phoneme must be /1/ or /r/ or /w/ or /j/. |

The result is that all words beginning with three consonants are words such as spring, string, squeal, splendid or stew. We never find words such as bdling, *sgteal or *wbtendid.