Phonetics vs. Phonology

1. Phonetics vs. phonology

Phonetics deals with the production of speech sounds by humans, often without prior knowledge of the language being spoken. Phonology is about patterns of sounds, especially different patterns of sounds in different languages, or within each language, different patterns of sounds in different positions in words etc.

2. Phonology as grammar of phonetic patterns

3. A given sound have a different function or status in the sound patterns of different languages

For example, the glottal stop [] occurs in both English and Arabic BUT ...

In English, at the beginning of a word, [] is a just way of beginning vowels, and does not occur with consonants. In the middle or at the end of a word, [] is one possible pronunciation of /t/ in e.g. "pat" [pa].

In Arabic, // is a consonant sound like any other (/k/, /t/ or whatever): [íktib] "write!", [daíia] "minute (time)", [a] "right".

4. Phonemes and allophones, or sounds and their variants

The vowels in the English words "cool", "whose" and "moon" are all similar but slightly different. They are three variants or allophones of the /u/ phoneme. The different variants are dependent on the different contexts in which they occur. Likewise, the consonant phoneme /k/ has different variant pronunciations in different contexts. Compare:
 
    keep
    /kip/
    The place of articulation is fronter in the mouth
    [k+h]
    cart
    /kt/
    The place of articulation is not so front in the mouth
    [kh]
    coot
    /kut/
    The place of articulation is backer, and the lips are rounded
    [khw]
    seek
    /sik/
    There is less aspiration than in initial position
    [k`]
    scoop
    /skup/
    There is no aspiration after /s/
    [k]
These are all examples of variants according to position (contextual variants). There are also variants between speakers and dialects. For example, "toad" may be pronounced [tëUd] in high-register RP, [toUd] or [tod] in the North. All of them are different pronunciations of the same sequence of phonemes. But these differences can lead to confusion: [toUd] is "toad" in one dialect, but may be "told" in another.

5. Phonological systems

Phonology is not just (or even mainly) concerned with categories or objects (such as consonants, vowels, phonemes, allophones, etc.) but is also crucially about relations. For example, the English stops and fricatives can be grouped into related pairs which differ in voicing and (for the stops) aspiration:
 
    Voiceless/aspirated
    ph
    th
    kh
    f
    s
    h
    Voiced/unaspirated
    b
    d
    v
    z
    ð
    (unpaired)
Patterns lead to expectations: we expect the voiceless fricative [h] to be paired with a voiced [], but we do not find this sound as a distinctive phoneme in English. And in fact /h/ functions differently from the other voiceless fricatives (it has a different distribution in words etc.) So even though [h] is phonetically classed as a voiceless fricative, it is phonologically quite different from /f/, /s/, // and //.

Different patterns are found in other languages. In Classical Greek a three-way distinction was made between stops:
 
    Voiceless/aspirated
    ph
    th
    kh
    Voiced/unaspirated
    p
    t
    k
    Voiced (and unaspirated)
    b
    d
In Hindi-Urdu a four-way pattern is found, at five places of articulation:
 
    Voiceless aspirated
    ph
    th
    h
    ch
    kh
    Voiceless unaspirated
    p
    t
    c
    k
    Voiced unaspirated
    b
    d
    etc.
Breathy voiced ("voiced aspirates")
    b
    d
    etc.
6. Shapes of vowel systems: some common examples:
 

Triangular:
(e.g. Arabic)
3 vowels
Triangular:
(e.g. Japanese)
5 vowels
i
u
i
u
e
o
a a
Triangular:
(e.g. Tübatulabal)
6 vowels
Triangular:
(e.g. Italian)
7 vowels
i
u
i
u
e
o
e
o
a a
Triangular:
(e.g. Bulgarian)
6 vowels
Rectangular:
(e.g. Montenegrin)
6 vowels
i
u
i
u
e
o
e
o
a
a

How many degrees of vowel height are there in Bulgarian? On the face of things, it appears to be not very different from Tübatulabal, which has three heights: three high vowels, two mid vowels and one low vowel. But if we look more closely into Bulgarian phonology, we see that the fact that schwa is similar in height to /e/ and /o/ is coincidental: the distinction that matters in Bulgarian is /i/ vs. /e/, /u/ vs. /o/ and // vs. /a/, i.e. relatively high vs. relatively low. As evidence for this statement, note that while all six vowels may occur in stressed syllables, only /i/, /e/, // and /u/ occur in unstressed syllables.

7. Phonology as interpretation of phonetic patterns: Fang (Bantu: Cameroon, Gabon, Equatorial Guinea)
 
Fang English Fang English
1) etf- shoulder 7) tm branch
2) vbi,v-bi hippopotamus 8) bikq back teeth
3) ndv() dam 9) eln water tortoise
4) kf-l tortoise 10) fq bag
5) kf- salt 11) t neck
6) kl rope 12) osn squirrel

Vowels in corpus:
 

i
y
 ?u expected but not found
e o
a

Further reading

Lass, R. (1984) Phonology: an introduction to basic concepts. Cambridge University Press.

Jakobson, R. (1962) The phonemic concept of distinctive features. In A. Sovijärvi and P. Aalto, eds. Proceedings of the Fourth International Congress of Phonetic Sciences. Mouton & Co. 440-455.

Jakobson, R. and M. Halle (1956) Fundamentals of Language. Mouton.

Kelly, J. (1974) Close vowels in Fang. Bulletin of the School of Oriental and African Studies 37, 119-123.