The study of phonetics is not simply the sounds that are made when a word is articulated, but also the way in which those sounds are created. Articulatory phonetics is a specific branch of phonetic study that looks at how the vocal tract produces speech sounds. Simply put, it is the study of the physiological characteristics of speech sounds: The production of any sound involves the movement of air through the vocal tract. This writeup is not intended to be a comprehensive resource for all the topics included, but more as an overview. The study of articulatory phonetics is a broad field. Consult nodes of specific value to get more in-depth on any of the topics covered herein. (Note: Please see International Phonetic Alphabet for a description of any IPA symbols used in this writeup. All sounds described in this writeup will be placed between / symbols.)
The majority of the items covered in this writeup will focus on English, save for a few things not easily explained through English or need further explanation. Tone languages, for example, will not be discussed at all (even though the vast majority of languages in the world are tone languages) because tone has no linguistic application in English.
In order to get a firm grasp of just how articulatory phonetics is described by linguists, a cursory glance at the bit players involved in the production of sound is required, starting with the front of the oral cavity (the lips) all the way down the throat to the glottis. Bear with me, there are more things between sucking in a breath and uttering Shakespeare than you might have guessed.
The Lips: These are those fleshy bits right in front of your face. You smile and with them, and you use them to shape the letters that are going to pop out. These bits of muscle won't help differentiate a /b/ sound from a /p/ sound (one is voiced, the other is voiceless--see the glottis, below), but they do help in distinguishing /b/ from a /v/ (one is a bilabial (two-lipped) consonant, the other is a labiodental consonant).
The Teeth: Your dentist loves these things, and so do linguists. The teeth act in two ways to create sound. The first is to act with the lips to create labiodental (bottom lip + teeth) consonants, the /v/ or /f/ sounds in English, and the second is to create interdental (between the teeth) consonants (such as the 'th' sound /θ/ in 'thin' or /ð/ in 'though').
The Alveolar Ridge: Right behind the teeth is a ridge of tightly skin-covered bone we call the alveolar ridge. This point of articulation is important for all alveolar consonants, when the tongue goes up to tap, glide along, or curl behind that ridge. See the alveolar consonants for more on this (isn't it convenient that alveolar consonants are made on the alveolar ridge? Linguists are economical with their words).
The Palate and Velum: At the back of the oral cavity lies the palate and the velum, sometimes distinguished as the hard and soft palate, but more often just as the palate and the velum. This is the rest of what is commonly known as the mouth that continues back to the uvula (the hanging down bit that we prod vigorously to make vomiting easier). The second half of the palate as a whole (the fleshy bit--prod with your tongue, you'll be able to feel where the bone ends and fleshiness begins) is the velum or soft palate. In this whole cavity, palatals, velars and uvular consonants are created.
The Glottis: If you know German, you know the glottis. This is the opening between the vocal cords, and is located in the larynx (the "voice box"), at the bottom of the throat-tube just past the tongue called the pharynx. The glottis is used in creating glottal consonants, and for glottal stops (such as the 'tt' in 'button' if your dialect doesn't pronounce the word /bʌtən/ but instead /bʌʔən/).
The vast majority of sounds that'll ever come out of your mouth (in terms of language--belches are only considered language when communicating during a football game, so far as I can tell) are pushed out from your lungs through your vocal tract and out your mouth. These are pulominic sounds (they came from your lungs) and egressive (since they were pushed out). That covers all the sounds you'll ever make in English--pulmonic egressive airstream mechanics.
Naturally, there are still a few languages in the world that use other airstream mechanisms to make their sounds. Ejective egressive sounds are made when air in the mouth is pressurized by an upward movement of the closed glottis and released suddenly, creating a sharp sound. Try it with 'p' to make an explosive popping sound. These ejectives are found in many American Indian and African languages.
There are several languages that use ingressive sounds, when the air is sucked into the mouth to make clicks (the tsk sound you heard when your great aunt chided you for eating too many sweets). Additionally, implosive sounds still exist in a tiny fraction of the world's languages, but so far as I can manage, they are impossible to portray in text format to the layman. But if you know Southern Bantu languages such as Xhosa and Zulu, or the languages of the Bushmen and Khoikhoi, you can know what I'm talking about.
Manners of Articulation - Consonants
There are two basic concepts linguists use to describe sounds being pushed out of your vocal tract. The first concept asks whether the sound is voiced or not, the second asks if it is nasal or not. "But I thought all sounds came out of the vocal tract, mister!" Hold on, I'll get to the nasal/oral distinction in a minute. The manners of articulation that follow exist to differentiate between the large variety of consonants and vowels that exist in all languages. The distinctions exist to help reproduce the sounds, the descriptors internationally excepted. Refer to the writeups on International Phonetic Alphabet for examples of these voiced/voiceless and nasal/oral sounds. I will attempt to keep my discussion to English.
Voiced and Voiceless Sounds
Quick, put your fingers in your ears. Seriously. Now say "ssssss" as a continuous sound. Okay, now say "zzzzzz." Could you feel the difference? The difference lies in your vocal cords. When they're apart, letting air stream right through the glottis and supraglottal cavities (see above), the sound produced is voiceless. The /s/ sound is voiceless. When the vocal cords are together, vibrating when the air is pushed through them, you get a voiced sound. Therefore, the /z/ sound is voiced.
Both the /s/ and /z/ sounds are alveolars, articulated in the same place in the vocal cavity. Try it out. Say 'sssssszzzzzz.' You'll notice that your tongue does not move from its position when shifting between the two sounds. The only difference is in how the vocal cords are acting.
Note: All vowels are voiced.
A subcategory of the voice/voiceless distinction is in aspiration. In IPA, this distinction is portrayed by putting a superscript 'h' next to the letter that is aspirated. In English, we make no distinction between the /p/ sound in 'pin' and the /p/ sound in 'spin.' To a speaker of English, they are allophonemic. There is, however, a difference. In 'pin,' the /p/ is aspirated, which means there is a brief period of voicelessness immediately after the /p/ sound is released--the vocal cords remain open for a very short time after the lips come apart. In 'spin,' however, the vocal cords start vibrating as soon as the lips open. (see chart below). In some languages (Hindi, for example), there is a phonemic distinction between aspirated and unaspirated consonants. Which means (made-up words follow) /pɪn/ and /pʰɪn/ are two completely different words, meaning totally different things, distinct only by their level of aspiration. If you think that's confusing, some languages in the Far East make no distinction between /r/ and /l/, just as we make no distinction between /p/ and /pʰ/.
bin | b i n
| (vibrating) |
spin s | p | i n
(apart) | | (vibrating)
pin | p | i n
| (apart) | (vibrating)
Note on word constructions:
/bɪn/ is completely voiced.
/spɪn/ is a voiceless /s/ and then an unaspirated, voiceless /p/. /ɪn/ is voiced.
/pɪn/ has a voiceless, aspirated /pʰ/.
Nasal and Oral Sounds
So, how we know whether or not a sound is voiced or voiceless, we need to know if it is a nasal or oral sound. We know that bilabial /p/ is distinguished from bilabial /b/ in that /p/ is voiceless and /b/ is voiced. However, /m/ is also a voiced bilabial. How is /m/ distinguished? /m/ is a nasal voiced bilabial consonant, made nasal because the velum (soft palate) is not in its raised position, allowing air to escape through the nasal cavity. In English, all nasal consonants are voiced, however nasal voiceless consonants exist in other languages.
In English, there are only three consonants that are nasal: /m n ŋ/.
Manners of Articulation - Vowels
So far, all of this has been about consonant sounds. Now the vowel must take center stage, as the glue that makes words singable. Or something. They're a bit trickier than consonants. When you're standing in front of the mirror and you make the /b/ sound, you can see your lips come together. When you articulate /t/, you can feel your tongue touching the alveolar ridge. We produce vowels, however, without any articulators touching, so it may be difficult to feel what is happening. The vowel sounds are created by the tongue (how high and what part of the tongue is involved) and by the lips' position.
When sounding a vowel, the tongue moves to a high, mid, or low position with its front, central or back part. Confused? Great, that's a good place to start. And while we're busy making funny noises in our bedrooms from the zzz-sss bit, try this one on: Say "hack, hah, hack, hah, hack, hah." You should be able to feel your tongue moving forward and backward in the lower part of your mouth. You've just demonstrated for yourself the vowels /æ/ (as in "hack," /hæk/) and /a/ (as in "hah," /ha/). The /æ/ is pronounced with the front part of the tongue low in the mouth, and /a/ is pronounced with the back part of the tongue low in the mouth. They are both considered low vowels, as they both are made with the tongue low in the mouth. A similar distinction exists between the /e/ in "bait," /bet/ and the /o/ in "boat," /bot/. Try the same experiment with those two words. Both those vowel sounds are made with the tongue at its middle height, the /e/ articulated with the front of the tongue, the /o/ articulated with the back, with rounded lips.
The second half of vowel creation is done with the lips, and is easy to see in the mirror. Take the vowel sounds from "beet," and "boot," which are /i/ and /u/ respectfully. Elongate the sound and look in the mirror. "eeeeeee-oooooooo." The lips are only rounded for the /u/ sound, the lips are tense and spread apart (unrounded) for the /i/ sound. For English, all back vowels (/u ʊ o ɔ/) are rounded, the rest are unrounded. The chart below shows the position of each vowel in English, as well as where the tongue is when the sound is articulated.
Part of the Tongue Involved
| FRONT --- CENTRAL --- BACK
HIGH i u
| ɪ ʊ
MID e o
| ɛ ə
| ʌ ɔ
LOW æ a
No doubt you've heard of diphthongs. They're an interesting breed of vowel, and can be defined simply as a vowel + a glide, making a two-vowel-sound vowel. All the vowel sounds up to this point are called monophthongs. That's awfully fun to say. A monophthong is a vowel with only (you guessed it!) one vowel sound. The /a/ in 'father' /faðər/. In words like 'bite,' however, you've got two vowel sounds. Take that /a/ and glide it into the /j/ sound (as in 'yes' /jɛs/), and you're left with a long 'i' sound, described conveniently enough as /aj/. Take the /a/ and merge it with a /w/, and you're left with /aw/ as in 'cow' /caw/. Take the /ɔ/ from 'caught' /kɔt/ and merge it with the glide /j/ and you have the vowel sound in 'boy' /bɔj/.
You didn't think you'd get away with only nasal consonants, did you? Of course not! Vowels, too, can be produced with the velum raised so that air is allowed to shoot out through the nasal passage. This occurs primarily when the vowel precedes one of the three nasal consonants /m n ŋ/. In phonemic transcription, a nasal vowel has a tilde diacritic mark, as in the case of 'cane' /kẽn/ or 'team' /tĩm/. (Note: If the tilde is not displaying properly in your browser, just imagine that a ~ is sitting on top of the 'e' and 'i' respectfully.)
In English, of course, this is all true. However, in other languages, a nasal consonant is not required to create a nasal vowel. French, Polish and Portuguese are notorious for this. The French word 'bon' has an 'n' when written, but in IPA it becomes a simple /bɔ̃/. In this case, the 'n' in the spelling indicates that the vowel is nasalized, but the sound /n/ is not pronounced.
Tense and Lax Vowels
There are four pairs of tense and lax vowels in the English language. In the second chart, describing the location of the tongue when pronouncing vowels, notice that the /i/ is higher than the /ɪ/. This not only points to the location of the tongue, but also the tense/lax variation. When you say the word 'beet' /bit/, notice that you tongue becomes tense on that /i/ sound, and the sound is quite long. Similarly, when you say 'bit' /bɪt/, notice your tongue is quite relaxed and a little bit shorter in sound. This characteristic is described as saying the /ɪ/ is a lax or shorter vowel, and the /i/ is a tense or longer vowel. The other three pairings are /e ɛ/, /u ʊ/, and /o ɔ/, paired tense and lax respectfully.
Just in case you have forgotten from the first couple of paragraphs, this is, by no means, a complete writeup on articulatory phonetics. This is just an introduction to the basic principles of the field. The writeup would simply be too long. I very much welcome any questions or corrections, feel free to send me a message, and I will be more than happy to fill you in on anything else if I can, or point you in the direction that might help you out.
Research done through An Introduction to Language, Seventh Edition by Victoria Fromkin, Robert Rodman, and Nina Hyams, A Biography of the English Language, Second Edition by C. M. Milward, and from my rather chaotic brain.