Vowel prowess and how it can help your singing

Understanding the importance of vowels can help a singer add colour and variation to their performance, explains top vocal coach John Henny.

In the singing world we hear so much about vowels: how to adjust them, which ones are best for singing higher and how they can help registration… the list goes on. Interest in this subject has led to more and more discussion about formants and harmonics. These can be a bit confusing at first, but are the building blocks of what we hear as vowels.

Put simply, harmonics are all the parts of the sound wave an instrument makes (think of them as a bunch of pitches at the same time). These harmonics give us the pitch and the colour of the sound wave.

The formants are the filter that the harmonics travel through. They are a measure of the resonance properties of an acoustic space. The formants of an acoustic space will boost the energy of some of the harmonics and attenuate or diminish others.

Spectograph a_e_i_o_u
Spectograph a_e_i_o_u

This selective boosting not only changes the colour of the tone but also gives us vowel perception. That’s all a vowel is, a perception that is created in our brains. This perception is created by different frequencies. When we hear a siren, we will often imitate it as “wee-woo, wee-woo”, yet there is no vowel being created by the alarm. It is simply the changing of the frequency of the siren that creates the vowel effect.

When we change vowels, we modify the frequencies we boost in the throat and mouth. We are changing the formants by adjusting the size and shape of our resonators (the throat and mouth) by adjusting our laryngeal height, jaw, tongue, and lips. These formant changes turn up or down different harmonics which then gives us the perception of changing vowels.

Thinking of vowels this way opens up new approaches. If a vowel is our shared perception of frequencies, then we can play with how far these perception spectrums can go.

In other words, there are multiple frequency combinations that will give us the perception of an “EE” or “AH” vowel.

This then provides us with the room to “play” with each vowel for colour, intensity, and -yes -registration.

I have found that the more deeply I listen to the vowels of different singers, the more variations and colours I hear. I then have more options when working with singers, especially advanced ones.

With beginning singers, your vowel options are often more limited, especially if there are registration issues.

If a singer is struggling with higher notes, the brighter, or more open, vowel variations become somewhat limited, with the rounder, more closed vowels, or vowel shades, being a better option. Conversely, if a singer is too light or breathy, the more closed shades of a vowel may not work so well, as they will tend to increase the singer’s issues. But, with advanced singers, the colour palette opens greatly.

I used to believe that wider, more open vowels were a prime cause of registration issues and would not allow students to get through their transitions in a “mix” balance. Now, while this is often true for beginning students, it is not necessarily true at all for advanced singers. As long as the singer has developed the proper balances of air and muscle, the vowel spectrum opens up.

We can now play with the formants of our resonators by adjusting our larynx, jaw, lips and tongue, which gives us almost limitless variations, vocal depth, intensity, and timbre.


Human vocal tract. From Wikimedia Commons, the free media repository
Human vocal tract. From Wikimedia Commons, the free media repository

I encourage you to try this in your voice; find a comfortable pitch and sustain the word “ME”. As you hold the pitch, move your larynx up and down, which will adjust the brightness and darkness of the vowel. Now move your tongue a little more forward and then start pulling it back. How far can the tongue move back while still giving the perception of “EE”?

Now, sing “ME” on a higher note. What do the tongue movements do now? You might find you cannot keep the tongue as far forward, especially if you want to belt with some intensity. You may need to move the tongue back to a greater degree than what you could on the lower pitch.

Why does this tongue position work well for the belt, but distort the “EE” perception in your lower range? It’s because the frequencies are different. Different pitches (and their accompanying harmonics) vibrate at different speeds, which changes the interactions with the formants.

So why am I prattling on about all this? I want you and your ears to become more open to the full range of what constitutes vowel perception and how many variations you can have while still delivering understandable text. I want you and, if you are a singing teacher your students, to experience more freedom in musical choices, especially the infinite beauty of vowel colour.


John Henny is internationally renowned as a "teacher of teachers". He has trained hundreds of voice teachers through masterclasses and his online Voice Teacher Bootcamps. John has been a featured columnist for Backstage Magazine, publishing more than 40 articles on vocal technique. He has also lectured and taught at USC, The Learning Annex, Mount Saint Mary's, and Paul McCartney's Liverpool Institute of the Arts. John's students range from beginners to superstars. He is available at his Music Academy in Glendora CA, and from anywhere via Skype lessons.