In his latest article, ELT pronunciation expert Adrian Underhill looks at consonants and how consciously rediscoving the ON and OFF voice buttons can benefit both your teaching and your students’ learning.

What are consonants?

From Latin con (‘with’) + sonare (‘to sound’)

A consonant /ˈkɒnsənənt/ is a speech sound that is not a vowel. It means ‘sounding with’ as consonants were thought of as sounds that were only produced together with vowels. Unlike vowels, a consonant is produced by some obstruction to the flow of air through the mouth.

There are 24 consonants in Standard British English. 15 of them are voiced. The voiced consonants are highlighted in the chart below:

                        Monothongs                                               Diphthongs


Consonants (voiced consonants are highlighted)

In this diagram the 15 voiced consonants are highlighted. In the first two rows of consonants you can see that each voiced consonant has an unvoiced counterpart to its left. This pairing is a very useful feature for learners of English pronunciation.

The voice button

In the previous two articles on diphthongs and monopthongs, we saw how to connect with the following three ‘muscle buttons’ in order to produce new and unfamiliar vowels:

1. The lips

2. The tongue

3. The jaw

However, consonant sounds require a fourth muscle button – the voice – because we have to switch the voice on and off to make voiced and unvoiced consonants. The technique I use consists of enabling my learners to do the following: discover the voice button so they gain control of voicing and unvoicing and ‘switch the voice on and off’; hear the different sounds produced; and know what they did and be able to do it again.

Here is the teaching sequence I use for consonants. Adapt this and make your own variations.

 A good place to start is with the unvoiced/voiced pairing /s/ and /z/.

1. I silently mime the sound /s/ with my lips, while also performing a sliding snake imitation with my hand. Amazingly, students watching this mime and gesture start to say /sssssss/. I point to /s/ on the chart. If they don’t say /s/ then I say the sound /s/ aloud, but I require them to listen to it internally in their inner ear before saying it aloud (See article my article on Diphthongs for more on Using Inner Imaging). Then I point to /s/ on the chart.

2. I then mime /z/ with my lips and with my hand I perform a pestering bee or mosquito. Students start to say /zzzzzzz/ and I point to /z/ on the chart. If not then I say it, as above.

3. I stop the mime. Using the chart only I slide the pointer back and forth between /s/ and /z/, and students make the two sounds accordingly. So we establish the sound / symbol correspondence.

4. I ask them to touch their fingers flat against the front of the throat, where the Adam’s apple (official term: laryngeal prominence) is located. Once again, I alternate the two sounds as I slide the pointer from /s/ and /z/ on the chart.

5. I ask the learners ‘What do you notice?’ and they say things like ‘voice’, ‘vibration’ … etc. I agree and suggest we call it ‘voice’.

6. I say ‘This is the voice switch, and we can put it ON or OFF.’ I show it in ‘ON position’, my fingers flat against my throat, and in ‘OFF position’ my fingers moved by 90 degrees. On, off, on, off, ‘like a light switch’.

7. Then I indicate /s/ on the chart and they say it, and I get them to continue the sound /sssss/. While doing that I move my hand (the voice switch) from the OFF to the ON position. Now they make /zzzzz/, then off and they make /sssss/ and so on several more times.

8. Now they should be intentionally and consciously switching their voice ON and OFF, simply in response to the visual cue of me moving my hand onto and off my throat. I now know – and so do they –that they have made the conscious rediscovery of their voice button, and they can therefore ‘voice’ and ‘unvoice’ at will. In addition, establishing this silent gesture to turn the voice on and off becomes an invaluable help in the toolkit of silently correcting pronunciation.

9. Now we have a gesture to indicate the voice ON and the voice OFF and we can immediately apply this to the discovery of the other seven voiced/unvoiced consonant pairs, for example /ʃ/ and /Ʒ/. I put my finger silently to my lips and mime the sound ssshhh and invite students to make it too. And when they do and I point to /ʃ/ on the chart.

10. While they continue this sound I indicate the voice switch ON and they find themselves saying /Ʒ/ the voiced pair. Then I indicate the /Ʒ/ symbol on the chart to show that is what they are saying.

All of these steps are demonstrated on my videos Pronunciation Skills: consonants part 2 /s/ and /z/ and Pronunciation Skills: consonants part 3 /ʃ/ and /Ʒ/

Extending the voice choice to other consonant pairs

Steps 1 - 10 may look long, but it takes about two minutes and is logical and simple. Using the voice ON/OFF gesture enables you to help learners to discover the other half of any voiced/unvoiced consonant pair. If they have one, they can immediately find the other. These pairs are clearly shown on the chart as follows:


Plosives are sounds that are made with closure of the mouth followed by a sudden release of air. In the first consonant row, the eight plosive sounds are arranged from front of the mouth (on the left) to back of the mouth (o the right), in four unvoiced/voiced pairs:

/p/ /b/

/t/ /d/

/ʧ/ / ʤ/

/k/ /g/

The four pairs indicate four positions in the mouth, from which eight sounds can be made using the voice ON or the voice OFF.


Fricative consonants are made by forcing air through a partially open passage. In the second consonant row the eight fricative sounds are arranged from front of the mouth (left) to back of the mouth (right), arranged in four unvoiced/voiced pairs:

/f/ /v/

/θ/ /ð/

/s/ /z/

/ʃ/ / Ʒ/

Again, the four pairs indicate four positions in the mouth, from which eight consonant sounds can be made using the voice ON and OFF.

Is the sound voiced or unvoiced?

Sometimes you cannot decide whether a consonant sound (in a word in connected speech) is voiced or unvoiced. For example the sound is it /s/ or /z/? Or is it /θ/ or /ð/?

The first test is to say the word aloud very slowly until you can feel and hear the voice switching ON and OFF on individual sounds. Having noted where the voice seems to come ON or OFF, you can check this by unvoicing that consonant if you are saying it voiced, or voicing it if you are saying it unvoiced. In other words do the opposite of what you did in test one. You’ll very quickly hear what’s going on, and what sounds right. This test works in English because every unvoiced sound has a voiced equivalent (except for /h/). Get students to do this too – it exploits the use of the voice button while enabling learners to make new sounds deliberately.

You can see me demonstrating the voice button on two of my mini training videos:

Pronunciation skills: consonants part 2 /s/ and /z/ and Pronunciation skills: consonants part 3 /ʃ/ and /Ʒ/.

Watch Pronunciation skills: Consonants part 1 Guided tour of consonants for a guided tour of consonants.

Watch videos 30–39 for demos of teaching the other consonants. All videos are accessible from here.

You can read further techniques in these two posts on my blog:

The story of sounds: Episode 8: Voice choice. Discovering the voice button

The story of sounds: Episode 9: Further discoveries using the voice button