Elliott Moreton, Department of Linguistics, UNC-Chapel Hill

This web page gives some ways you can tell, without using X-rays, what is going on inside your vocal tract when you produce different speech sounds. Many are standard techniques. Some I just made up and tested on myself, so they may not work as well for you. All are suitable for in-class demonstrations.

Suggestions are welcome. My examples are in English, but I'd be interested to hear suggestions from people teaching phonetics to non-Anglophones. Also, if you know of anyone I should be crediting as the inventor of a particular technique, please let me know.

You will need the following equipment:

• A mirror. Two mirrors is even better, since they let you look at your head and neck from odd angles. You can get a pocket-sized double folding mirror at the drugstore for $2 in the U.S. (There are also apps that turn a smartphone into a mirror.)

• A long, thin, sanitary object to use as a probe. There are two main possibilities, each with its own advantages:
  • Uncooked spaghetti. Advantages: Can be inserted into mouth, then snapped off at lips to yield measurable fragment. Thin. Drawbacks: Fragile, bendy (may reduce accuracy).
  • Bamboo skewers, which you can get by the hundred at the supermarket. Advantages: Rigid, durable. Disadvantages: Can't be snapped off, sharp at one end.

• A strong light. A good overhead light or desk lamp will do, but a small flashlight is even better.

• A ruler. Metric is best.

• A watch that can do seconds.

• Clean fingers. You will be sticking them in your mouth.

The major articulatory properties of oral vowels are height, backness, and rounding. We'll take them from most to least visible.

rounding

Watch your lips in the mirror as you slowly say he, hay, ha, haw, hoe, who. How much tooth can you see for each one? Why does a photographer ask you to say cheese?

Pay attention to the feeling in your lips when you make a rounded vowel. They will feel tighter, more clenched, as the vowel gets more rounded. Try saying each one of the example words alone and drawing out the vowel as long as you can. Which ones make your lips feel tired? Notice that the rounded vowels are not all equally rounded. Can you spot a pattern?

height

Watch your chin in the mirror as you say seat, sat, and then again as you say boot, bought. Most American English speakers will be able to see a clear difference in jaw height. If you touch your chin while making the vowel in sat or bought, and then say seat or boot, you won't be able to feel your chin any more.

Once you can see and feel the difference between a high and a low vowel, try mid vowels: seat, set, sat or boot, boat, bought. If you have trouble seeing the difference with chin height, try looking at your lower lip, or at the size of your mouth opening.

Use your mirror to watch the fleshy underside of your lower jaw as you say the example words. You may be able to see it swell alarmingly for the high vowels (try pronouncing the words with your teeth clenched). Why do you suppose it this happens?

backness

This is the hardest feature to observe, because you actually have to see or feel the tongue itself, which in many cases (especially rounded vowels) is hard. Here are a couple of not-quite-ideal methods.

Open your mouth wide, as if you were yelling, and say the vowels in sat and sought. Use the mirror to keep an eye on your tongue. You should be able to see it move quite some distance back and forth.

Now try with the vowels of bet and boat. You may not be able to see the tongue for boat because of lip rounding, so try this: While saying the vowel of boat, stick spaghetti or skewer into your mouth until it touches your tongue. Now switch to the vowel of bet. Your tongue will push the probe out of your mouth! Try again with the vowels of boot and beet.

(You can use the probe to measure the horizontal distance from the lips to the tongue body for mid and high vowels. Compare this distance for the vowel in American English boo with that in French bout. There should be a considerable difference.)

Another method is to make the vowel, hold it, and de-round your lips until you can see your tongue. It is best to do this silently. If you pronounce the vowel aloud, and it is rounded, then you will hear it change as you unround your lips and may unconsciously compensate for that by moving your tongue.

Labial articulations are extremely easy to see. Just watch your lips in the mirror as you say pa, ba, ma, fa, va, wa. Compare [p b m] with [f v]. Which lip moves, and where does it move too? How much tooth can you see? Now compare [p b m] with [w]. What's different about the lip action?

Dental articulations are also easy: Watch your tongue as your say thy thigh. Which is the active and which is the passive articulator?

Alveolar consonants are hidden behind your teeth.

You can easily feel your alveolar ridge with your tongue; it's the thick roll of bone right behind your upper front teeth. Most American speakers strike it with their tongues when they say tot, for instance.

It takes two mirrors to see your alveolar ridge. If you have one of those beam-me-up-Scotty compact mirrors (two small mirrors hinged together like a chair), fold it to an angle of slightly less than 90 degrees. Then put one of the mirrors into your mouth, glassy side up, like you were going to take a bite out of it, and look in the other (near-vertical) mirror. You should see a view of your mouth from below -- the horizontal mirror reflected in the vertical one. (It might be dark in there. Use a flashlight, or stand under a strong light so that the horizontal mirror reflects the light up into your mouth.) The bulge there is your alveolar ridge. Hold your breath, so as not to fog up the mirrors, and mime saying [nnnnnn], or [ssssss], or any other alveolar consonant.

Alveolars are different from palato-alveolars in that you can say an alveolar with your mouth wide open. How come? (Try it, and watch in the mirror.)

Explore the roof of your mouth with your finger. The front half is hard and bony; this is your palate (or sometimes "hard palate"). Around the point where your teeth stop, the bone gives way to soft, slimy muscle. This is the velum. (For more about the velum, see below under "nasal".)

Palato-alveolar sounds are the hardest to see. They are made on the back side of the alveolar ridge, where it is steepest, hidden behind not just the teeth but the alveolar ridge itself, and you can't open your mouth while saying them. Even worse, many speakers conceal more by rounding their lips for palato-alveolars. (Do you?)

If you have enough of an overbite, you may be able to get a glimpse of the tongue in action. Smile to retract your lips, shine the light into your mouth from below, and slowly repeat (silently, so as not to fog the mirror) the word touch. You can see how far back the palato-alveolar place is compared to the alveolar place. Are you using the same part of your tongue as the active articulator?

Velar

Even further back, but easier to see than palato-alveolar, because you can open your mouth fairly wide while making them. Do this, and watch in the mirror as you slowly repeat [ga gi ga gi]. What happens?

All places:

Make each articulation, and push the probe in until it won't go any further. Measure how far it is from the closure to the lips. If you're using spaghetti, break it at the lips each time to make fragments showing the distance at each place of articulation.

What is the lowest resonant frequency of a half-open tube of that length? If you have a spectrograph handy, look for the lowest spectral peak of the stop-release burst, or of the frication noise, for that place of articulation.

Vibration of your vocal folds is easiest to observe with fricatives, because they come in voiceless and voiced versions and can be prolonged. Put your left hand on your throat, raise your right hand, and repeat after me: [ssssssssss zzzzzzzz ssssssss zzzzzzzz]. You should press firmly for best results.

It is very difficult to see any difference between voiced and voiceless from outside, since the muscles which open and close the glottis are deep inside your neck. If you know of a way, please tell me!

A vowel or consonant is nasal if air comes out your nose when you make it. You can detect air coming out your nose in four ways.

1. Say the sound while pinching your nose shut. If you can say it okay, then it isn't nasal. If you have trouble, then it is.

2. Hold your mirror just underneath your nostrils. Do this and say [nnnnnnnnnnn]; then quickly look at the mirror. You should see it all misted over. Now try a non-nasal sound like [rrrrrrrrr]; this time there should be no mist. (Caution: Be sure to hold your breath as soon as you finish the sound -- otherwise, your regular nasal breathing will mist the mirror!)

3. Hold your finger horizontally under your nostrils and say [nnnnn] loudly. You may be able to feel the nasal airflow.

4. (This one is weird, but dramatic.) Hold the bridge of someone else's nose between your thumb and forefinger. Ask them to tell you about their recent trip to Toronto. You will feel a most disturbing buzz every time they hit a nasal consonant.

The valve that lets air out your nose is the velum, which is part of the roof of your mouth. You can find your velum with your finger, as described in the section on "Consonant Place of Articulation". You can also find it by eye: Open wide, look in with the mirror, and find your uvula -- the stalactite at the back. It hangs down from the velum. Watch as you repeat [aaaa a~a~a~a~] (i.e., oral and nasalized [a]). The velum moves up and down to close and open the velopharyngeal port (the valve). What happens to velum and tongue when you breathe through your nose? your mouth? both simultaneously?

Take a deep breath through your nose. Where do you feel coldness?

American English has only one sound where air escapes around the sides of the tongue, and that's [l]. To see this, pronounce [llllllll], and then (keeping your tongue where it was) inhale strongly. You will feel part of your tongue get cold as the spit evaporates. Try pronouncing [l] with your mouth as open as possible. What is the place of articulation? Where do the lateral openings begin?

Some speakers make [l] symmetrically; others have their tongue to one side or the other. Still others have a non-lateral [l], with air going over the center of the tongue. What do you do?

Experiment with [l] in different syllable positions: lah versus all. Stick a probe in through one of the lateral openings, and feel what the back of your tongue is doing in the two different [l]s.

This is the only sound in which there is no significant obstruction to the passage of air anywhere in the vocal tract. With other sounds, there is an obstruction either at the vocal folds (vowels), or in the mouth (voiceless consonants) or at both (voiced consonants)

Take a deep breath, and see how long you can prolong a random vowel, a random voiceless fricative, or a random voiced fricative. (You should be able to make 30 seconds easily!) Now try the same for [h]. For which one do you run out of air first?

At the base of your throat, below your larynx and right between your left and right collarbones, is a little hollow. On the other side of the skin there is your windpipe. Watch that hollow in a mirror as you hold your breath and force with your lungs. The harder you try to exhale through a clenched glottis, the shallower that hollow will be it acts like a pressure gauge. Now compare how it behaves when you say a vowel (or some other sound) versus when you say [h]. The louder you speak, the more dramatic the difference will be (why?).

This section collects together various low-tech ways of observing articulation. Most were used in the exercises above. Practice using them to observe your own speech, and you won't have to memorize any feature charts.

• Look at lips, tongue, teeth, jaw, Adam's apple, fleshy underjaw, hollow of the throat.

• Probe around in your mouth with fingers, spaghetti, or skewer.

• Make a sound, hold it, and retract your lips to get a better view.

• Make a sound with your mouth open (as if shouting) and look in the mirror to see where your tongue is. (If you can do this at all, you instantly know the sound isn't palato-alveolar.)

• Feel with your mouth nerves where your tongue is and what it's touching.

• Pinch your nose to see if air is trying to flow out of it.

• Feel with your hand whether your nose is vibrating (nasals) and whether your vocal folds are vibrating (voiced sounds).

• Mime a sound and inhale through your mouth to see which parts of the mouth feel cold.

Last updated 2023 October 11 (W)