What happens when we make a sound?

We rely on our voice every day to communicate with others, but just as we walk without thinking about it, we usually speak without thinking about how our body makes it happen. However, knowing how we make sound is useful to maintaining the health and effectiveness of our voices both when singing and in everyday life.

THE MAIN PARTS OF VOICE PRODUCTION

• The Power Source: Your Lungs

• The Oscillator: Your Larynx (Voice Box)

• The Resonators: Your Throat, Nose, Mouth, and Sinuses

• The Articulators: The Lips, Teeth, and Tongue

The Power Source

The power for your voice comes from air that you exhale moving through the vocal cords. When we inhale, the diaphragm lowers and the rib cage expands, drawing air into the lungs. This should be totally relaxed, shouldn’t make a huge sound and should not involve a substantial upward shoulder motion. A free ribcage will expand 360 sideways forwards and back. Because of the placement of our heart, most of the lung tissue is at the back of our body, we must remember that our ribcage must expand backward as well as forwards.

MYTH BUSTER: We cannot actually breathe into our belly as the lungs end at the bottom of our ribcage. However, this is a useful mental tool to help us avoid breathing with tension. As we exhale, the process reverses, the diaphragm moves up (and can move up to 12 cm up the body) and air exits the lungs, creating an airstream. This airstream provides the energy for the vocal folds in the voice box to vibrate and produce sound. Controlled air flow is essential when singing, it determines volume, clarity, and tone.

The Oscillator

We are talking about the larynx (or voice box) which sits on top of the windpipe. The primary function of the larynx is to in fact stop us breathing in food. It contains two vocal folds (also known as vocal cords) that open during breathing and close during voice production. A type of lid called the Epiglottis closes over the vocal chords when we swallow. When we produce sound, the airstream passes between the two vocal folds that have come together. These folds are soft and are set into vibration by the passing airstream, think of when you blew through grass as a child. They vibrate very fast from 100 to 3000 times per second, depending on the pitch of the sound we make. However many times per second the vocal cords vibrate is the pitch sung, e.g. 100 times per second is 100Hz. Pitch is determined by the length and tension of the vocal folds, which are controlled by muscles in the larynx.

The Resonators

By themselves, the vocal folds produce a noise that sounds like simple buzzing, much like the mouthpiece on a trombone. All of the structure above the folds, including the throat, nose, and mouth, are part of the resonator system. We can compare these structures to those of a horn or trombone. The buzzing sound created by vocal fold vibration is changed by the shape of the resonator tract to produce our unique sound. We all have our own unique tone determined by the shape and size of the spaces in our body, but we can change the sound by changing the shape of our mouth, tongue and vocal tract (the tubes that make up our throat). It is important to note that although it often feels like the sound is in the “chest” or “head”, this is not actually where the air is, but the feeling the sound in these areas is a useful mental tool in creating different tones.

The Articulators

The last place the sound is created is at the articulators. Or to put it simply, your lips, teeth and the tongue. These are what allows us to form consonants and ultimately words.

• Plosives (P, B, C, D, T, Q) – A voiceless sound where the air builds up behind an area of the mouth or vocal tract then released explosively.

• Nasal (M, N, Ng) – A voiced sound that requires the vocal cords to be used. The air is again trapped by a part of the mouth or vocal tract and escapes through the nose.

• Affricates (ss, vvv, fff) – can be voiceless or voiced. Air builds up behind an area of the mouth or vocal tract and is released slowly.