chapter 11.6: allophones
Allophones are non-meaningfully distinct variations within phonemes that do not provide a contrastive difference with each other. These are the sound variations that will fail the minimal pair test. While there are many tiny variations within the phonemes we make while we speak, many of these are two unimportant or unnoticeable to discuss. Here instead we will see some examples of “complementary distribution.”
Contrastive vs Complementary Distribution
Phonemes occur in contrastive distribution with each other. For example, a /p/ and a /t/ can both occur at the beginning of a word in English, such as “pin” and “tin.” Because these two sounds contrast with each other, we recognize these two words as distinct in meaning (they pass the minimal pair test). Therefore, /p/ and /t/ are each phonemes that will contrast with each other when placed in identical positions.
Other sounds, however, are found in complementary distribution, meaning that they never occur in identical positions and so will never contrast with each other. These sounds will therefore not be recognized as individual phonemes, but will be allophones, of the same phoneme — non-meaningfully distinct or non-contrastive variants of a single phoneme.
As an example of complementary distribution, the word “pin” begins with the phoneme /p/. When we examine this sound in more detail, we find that it comes with a heavy breath of air: it is an aspirated example of the phoneme /p/, which we can write as [ph]. All examples of the phoneme /p/ in English that occur in word-initial position will also be aspirated. If we compare it with the /p/ found in the word “spin,” we will find that this /p/ does not have aspiration, so we can write it as [p]. Both [ph] and [p] are allophones of the phoneme /p/ which are non-contrastive because they will never occur in identical positions. [ph] occurs in word-initial positions, while [p] occurs following [s]. A third allophone of /p/ occurs in word-final position, such as in the word “tip.” This /p/ is often pronounced “unreleased,” i.e., with no opening of the lips after they close. It can be written as [p̚]. This [p̚] will never be found in word-initial position. Instead of contrasting, then, these three examples of /p/ complement each other to make up the entire set of realizations of the phoneme /p/.
Another way to think of the distinction between phonemes and allophones is that phonemes provide a mental concept for listening while the allophone is the real-world production of the concept.
Other examples of allophones
/t/ (voiceless, dental stop)
The phoneme /t/ has the same three variants as /p/ above, as you can see in the words top, stop, and pot, but it has others as well, such as those found in the words writer and written. In the first of these, the /t/ is medial (in the middle of a word) and occurs after a stressed syllable. In this position in American English the /t/ is often produced by a simple alveolar flap, produced by a quick “flap” or “tap” of the tongue against the alveolar ridge; it is thus called an alveolar flap. The symbol for this sound is [ɾ]. This sound sounds very much like a [d], so much so that for most people, the words writer and rider are difficult to distinguish from each other. British speakers, however, preserve the [t] here, so that writer and rider can be distinguished. Another allophone of /t/ is found in the pronunciation of the word written. Most American English speakers do not actually use an alveolar sound at all for the /t/ in this word, but instead stop the air in the glottis, the space between the vocal cords: this is the glottal stop, written [ʔ]. It is heard in the word “uh-oh,” which in IPA would be written something like [ʔə ʔo]. In American English, it appears as an allophone of /t/ whenever the /t/ occurs after a stressed syllable and before /n/ (as in kitten, mitten, bitten); some pronunciations of didn’t also use it for the medial /d/. In some dialects of British English, it occurs before or after the approximants /l/ and /ɹ/, as in the words bottle [bɒʔəl], forty [fɔɹʔi], etc. American English speakers sometimes use it for words that end with /t/. For example, people might say at as either [æt̚] with an unreleased /t/ or as [æʔ] with the glottal stop. This makes a total of five common allophones for the phone /t/: [th], [t], [t̚], [ɾ], and [ʔ].