Phonetics and Phonology: The Sounds You Never Knew You Were Choosing

Hold your hand in front of your mouth and say "pin", then "spin". In "pin" you feel a small puff of air on your palm. In "spin" you feel almost none. Those are two different sounds, as different in your mouth as a "p" and a "b" are to someone else. Yet you have probably never noticed, and an English speaker would call both of them "the letter p".

A Hindi speaker would not. In Hindi the puffed and unpuffed versions separate words: pal means "moment" and phal (with the puff) means "fruit". The mouth makes the same two sounds in both languages. What differs is which differences the language has decided to count. That gap, between what the mouth does and what the mind keeps track of, is the whole subject, and it is why linguistics courses start here.

Place, manner and voicing: every consonant is three choices

A consonant is a gesture that blocks or narrows the air on its way out. Phonetics describes it with three answers. Where is the narrowing (place)? Lips for [p], tongue tip behind the teeth for [t], the back of the tongue against the soft palate for [k]. How does the air get past (manner)? Stopped completely and released (a plosive: [p t k]), forced through a slit with hiss (a fricative: [s f]), sent through the nose (a nasal: [m n]), and so on. And is the larynx buzzing (voiced: [z b m]) or silent (voiceless: [s p])?

Those three answers are enough to name nearly every consonant in the world: [s] is a voiceless alveolar fricative, and [z] is the same with the buzz switched on. Put your fingertips on your throat and hold "sss", then "zzz". The International Phonetic Alphabet, founded by language teachers in Paris in 1886, is a chart of this idea: columns for place, rows for manner, voiceless and voiced symbols side by side.

Without JavaScript: [p] voiceless bilabial plosive; [b] voiced bilabial plosive; [s] voiceless alveolar fricative; [z] voiced alveolar fricative; [m] voiced bilabial nasal.

What a graduate remembers is that the chart has gaps with reasons. English has no voiceless nasal phonemes (a silent [m]), though languages such as Burmese do. A bilabial fricative [ɸ] is rare in English but is the "f" in Japanese fu. Two places can be used at once: the English "w" is made with the lips and the back of the tongue. And note what the chart does not contain: letters. Spelling is a different system, which is why English ough can be pronounced six ways.

Vowels are a map, and formants are the coordinates

Vowels have no narrowing at all, so "place" is not the right question. Instead, a vowel is a shape of the mouth: how high the tongue is (and so how open the jaw), how far forward it is, and whether the lips are rounded. Say "ee, ay, ah" slowly and feel the jaw drop. Say "ee" then "oo" and feel the tongue slide back and the lips round.

The shape matters because the mouth is a resonating tube. The buzz from your larynx contains many frequencies, and the tube boosts a few of them. Those boosted bands are formants. The lowest, F1, goes up as the jaw opens: "ee" has a low F1 and "ah" a high one. The second, F2, goes up as the tongue moves forward: "ee" has a high F2 and "oo" a low one. Plot F1 downward and F2 right-to-left and you get the familiar vowel chart, drawn from acoustics instead of from tongue positions. This is one of the cleaner results in the field: the old tongue-position chart and the formant plot roughly coincide.

Without JavaScript: [i] has F1 about 240 Hz and F2 about 2400 Hz; [a] has about 850 and 1610; [u] has about 250 and 595.

This is also why the symbols mean less than they look. Your "ee" and mine differ in the numbers; the IPA labels a region of the map, not a point. And a vowel in your language is judged against its neighbours: Spanish has five vowels and spreads them wide; a language with fifteen must crowd them.

Phonemes: the sounds a language counts

Now the turn from phonetics to phonology. The mouth can make a near-infinite number of sounds, but each language carves them into a small set of phonemes: categories that change meaning. Two sounds are different phonemes if swapping one for the other can turn one word into another. The test is the minimal pair: pat and bat, which differ only in voicing, prove that English /p/ and /b/ are different phonemes. (Slashes mean phoneme; square brackets mean the actual sound.)

If two sounds never swap words, they are allophones of one phoneme. The puffed [pʰ] of "pin" and the unpuffed [p] of "spin" are allophones of English /p/: the puffed one comes at the start of a stressed syllable, the plain one after /s/. Their distributions don't overlap (complementary distribution), so the language never needed to use them to tell words apart, and speakers never learned to hear the difference. The same pair of sounds is two phonemes in Hindi, Thai and Korean.

Without JavaScript: Hindi pal [pəl] "moment" and phal [pʰəl] "fruit" are a minimal pair, so [p] and [pʰ] are two phonemes. In English they are allophones of /p/. In Spanish [d] and [ð] are one phoneme; in Japanese [t], [ts] and [tɕ] are one.

This is why a learner's "accent" is not carelessness. A Japanese speaker, whose language has a single liquid phoneme, has no trained category for the English /l/-/r/ split; a Spanish speaker hears [d] and [ð] as one sound and will not notice that they have been using both all their life. Babies start with every contrast open and, by about a year, tune toward the ones their language uses.

Rules over features: why "cats" and "dogs" end differently

Phonology's second discovery is that sounds change according to rules that refer to features, not to individual sounds. Take the English plural. Spelling shows an "s" for all three: cats, dogs, buses. In speech they are different: cats [kæts], dogs [dɔɡz], buses [ˈbʌsɪz]. Nobody teaches children this, yet they apply it to words they have never heard. In Jean Berko's 1958 "wug test", children shown a picture of one invented creature and then two supplied "wugz", with the voiced ending, to a word that did not exist.

The rule has two steps, and both are about features. After a sibilant (a hissing sound like [s z ʃ ʒ tʃ dʒ]) add the extra vowel, [ɪz], because otherwise the two hisses would run together. Otherwise copy the buzz of the last sound: voiceless stays voiceless ([s]), voiced stays voiced ([z]). The plural suffix quietly agrees with the sound before it. Other languages do similar things with bigger consequences. In German, voiced stops lose their voicing at the end of a word, so Rad "wheel" and Rat "advice" are both pronounced [ʁaːt]; the plurals Räder and Räte bring back the difference.

Without JavaScript: cat gives [s] (voiceless ending), dog gives [z] (voiced), bus gives [ɪz] (sibilant).

Tone: when pitch spells the word

English uses pitch for questions and moods, but not to tell words apart. In a tone language the pitch contour is part of the word, as much as its consonants. WALS, the World Atlas of Language Structures, sorts 527 languages in Maddieson's chapter on tone: 307 have no tones, 132 have a simple system (usually two contrasts, high and low), and 88 have a complex one. So well over a third of the sample uses pitch for words, and that is not just East Asia: Yoruba and Igbo in West Africa and Mixtec in Mexico are tonal.

Standard Mandarin has four tones. The syllable ma is "mother", "hemp", "horse" or "scold" depending on whether the pitch stays high, rises, dips and rises, or falls sharply. Cantonese counts six, in the common Jyutping description: the syllable si alone covers "poem", "history", "try", "time", "market" and "matter". Linguists write contours with Chao's five-level number system, 5 being the top of the speaker's range, so Mandarin's tones are 55, 35, 214 and 51.

Without JavaScript: Mandarin ma: 55 mother, 35 hemp, 214 horse, 51 scold. Cantonese si: 55 poem, 25 history, 33 try, 21 time, 23 market, 22 matter.

Clicks, and how big a sound inventory can be

Languages differ in how many sounds they count. WALS (Maddieson) puts 563 languages in five size bands of consonant inventories: 89 are small (6 to 14 consonants), 122 moderately small, 201 average (about 19 to 25), 94 moderately large and 57 large (34 or more). The extremes are 6 consonants in Rotokas, spoken on Bougainville Island in Papua New Guinea, and up to 122 in the Khoisan language !Xóõ, now usually called Taa, spoken mainly in Botswana by about 2,500 people.

Much of Taa's size comes from clicks, which are made by trapping a pocket of air with the tongue and releasing it with a suction pop. Clicks are phonemes in many languages of southern Africa (Zulu, Xhosa, Nama, Taa) and in two languages of Tanzania, Hadza and Sandawe. They are not odd mouth-noises. Xhosa, with several million speakers, writes three click places as c, q and x, so ucango "door", uqeqesho "training" and the first sound of isiXhosa itself all start with clicks. And you already make clicks: a disapproving "tsk tsk" is the dental click, a horse-clop is the lateral click, and a kiss is the bilabial one. English just doesn't use them in words.

Without JavaScript: dental ǀ is "tsk"; lateral ǁ is the horse-clop sound; bilabial ʘ is a kiss; alveolar ǃ and palatal ǂ are popping clicks.

A last fact about inventories: they are not the whole story. Two languages with the same sounds can have very different phonotactics, the rules for how sounds may combine. English allows the cluster "str" at the start of a word; Japanese basically allows consonant, vowel, consonant, vowel, and a Japanese speaker will insert vowels into English words, turning "street" into sutoriito. Phonology covers inventory, combination and change together.

What a graduate just sees

• Every consonant is a place, a manner and a voicing; a gap in the chart usually has a reason.
• A vowel is a point on a map; F1 follows jaw opening, F2 follows tongue frontness.
• The unit that matters is the phoneme: a sound counts only if it can change a word.
• Two sounds that never appear in the same place are usually one phoneme, and the speaker can't hear the split.
• Rules refer to features (voicing, sibilance), which is why the plural agrees with the sound before it, and why it applies to made-up words.
• Spelling is not sound; a foreign accent is a trained set of categories, not carelessness.
• Tone and clicks are ordinary equipment for well over a third of the world's languages, and the size of sound inventories ranges from about 20 to over 100.

Where it shows up next

• Morphology (36/22): the English plural has three shapes; Turkish vowel harmony is a phonological rule that reaches into word-building.
• Historical Linguistics (36/25): sound change is regular, which is how related languages are proved to be related.
• Sociolinguistics (36/26): accents are patterns of allophones and vowel shifts, and they carry social meaning.
• Language Acquisition (36/27) and Psycholinguistics (36/28): infants tuning to their language's contrasts; how listeners recognise words in noise.
• In the world: speech recognition and text-to-speech engines, speech therapy, dictionary pronunciations, and the design of writing systems for languages that have none.

If you want to go deeper

• 📘 Textbook (phonetics). Peter Ladefoged and Keith Johnson, A Course in Phonetics (7th edition, 2015): the standard first course, with practical transcription.
• 📘 Textbook (phonology). David Odden, Introducing Phonology (2nd edition, Cambridge University Press, 2013), which teaches the problem-solving method with data from many languages.
• 📘 Gentler. Peter Ladefoged and Sandra Disner, Vowels and Consonants, an accessible tour of the world's sounds.
• 🌐 Free text. Essentials of Linguistics, 2nd edition (Anderson and colleagues, McMaster University), a free open textbook with phonetics and phonology chapters: ecampusontario.pressbooks.pub/essentialsoflinguistics2.
• 🌐 Hear the real thing. The interactive chart at ipachart.com plays recorded speakers for each symbol.
• 🌐 Free course. MIT OpenCourseWare 24.900 Introduction to Linguistics (Spring 2022).