How The Voice Works

Written by: Nimra Khan / Voice / February 22, 2023 / 8 minutes read

I’ve always found it helpful and interesting to discuss how different parts of speech actually work in the body. This can be helpful for clients to picture in their minds what an SLP is seeing, and for clients to be on the same page about why it may be important to work on areas such as breath support or enunciation. I wanted to take some time today to provide some summaries about the physiology of speech.

The 3 sub-systems

As humans, we love to group things together. A good example of this is creating 3 main parts of speech which, when they work together well, provide a lot of the harmony that makes our voices strong. These 3 parts are the oral cavity, voice box (larynx), and lungs. Let’s dive into each section a bit more.

Part 1: Oral cavity – articulation and resonance 

As the name suggests, we are looking here at the mouth, including the tongue, teeth, and lips. How all of these parts coordinate together SHAPES the sound that we use. Resonance is also an important part of this. Resonance involves where the sound is vibrating (the amplification of sound waves) – either in the mouth or nose. Change in resonance can be affected by the position of your tongue (higher tongue position can make it easier to have a higher/brighter resonance, meaning more sound bouncing around in the nasal cavity). 

Another way to impact volume through your focus on the oral cavity is to enunciate better. If you want to increase volume/sound louder, then create more space! A common mistake is using good breath support but having a very small space that your mouth moves in. 

Part 2: Larynx – vocal fold vibration 

The vocal folds are vital for voice, and help create a sound unique to your voice. They can be described simply as two membranes that, when meeting together with air passing between them, create a vibration that you can shape. Place a hand on your throat and say ‘zzzzz’ – you should feel a ‘buzz’. Now say ‘ssssss’ – you shouldn’t feel anything. That’s because ‘z’ is a sound that requires vocal fold vibration, whereas as ‘s’ is not. 

It should be noted that vocal folds meet together at 100+ times per second when voicing, so they do a lot of work for our voice! Since they are such a small structure, that means that it can be easy to cause strain and/or damage. Vocal misuse due to speaking over long periods with increased effort can make your voice hoarse over time and make it difficult to increase your volume. I have worked with teachers and other professional voice users who have experienced vocal damage over time. Your habits over time are crucial to this. Often, we think of voice damage as a sudden event (i.e. one night of speaking very loudly and feeling hoarse the next day), but the long-lasting change can be seen over time. Due to this, it can be frustrating, but reversing or reducing the damage also takes time and slow changes to habits. 

Part 3: Lungs 

This might be the most self-explanatory, but you may be surprised by how crucial your method of breathing can be to your voice. Keep in mind, as I mentioned above, that an outbreath is needed to speak. If someone holds a lot of tension in their chest or abdominal muscles, they can often accidently ‘hold’ their breath and put more strain on their larynx. Holding breath can often mean restricting how much your abdominal and chest muscles move. Read more about types of breathing here. 

If you want to increase volume/sound louder, then create more space! A common mistake is using good breath support but having a very small space that your mouth moves in. 

How can breath support help my voice?

Breath support/control are essential for everyday speech, eating, exercising and relaxing. This is done through coordinated airflow, which means that different speaking demands will require changes in breath support. For example, when speaking one-to-one versus in a loud environment where you have to project your voice. 

There are different ways to help improve this support, depending on each individual’s needs and areas of difficulty. Some areas can include:

• Increasing the available breath/lung capacity

• Increasing use of abdominal (‘belly’) breaths, rather than shallow ‘chest’ breaths 

• Strengthening and coordinating muscles for posture 

• Increasing one’s awareness of their own breath

All of these methods allow more control and awareness of breath, which creates better airflow for voicing, which in turn allows you to control your resonance as well. Think of this as another way to place less effort on muscles of your head and neck, as well as less effort on your voice box. This can create a lot of positive change over time, especially if your voice feels hoarse, strained or painful when speaking. 

Vocal hygiene, how you take care of your voice, is also very important – read more about that here.  

Impact of other physical changes -- Acid reflux

Reflux can begin for many different reasons, including stomach bugs, bad reactions to medication, and other gastrointestinal issues. It involves acid from the stomach coming up into the oesophagus or even into the mouth. It can sometimes be silent, but you can often tell it is happening when you feel heartburn, a need to ‘clear’ the throat, and sometimes an increased need to swallow or increased burping. 

As the trachea and oesophagus are beside each other, reflux from the stomach can spill over onto the vocal cords (voice box). As you can imagine, reflux burns the lining of the throat, so it can be painful and cause more dryness. It’s important to manage this if it occurs for you to see mor improvement in voice. Managing usually involves medications to reduce acidity and also managing diet and lifestyle to help reduce the factors that trigger your reflux. Read here for some other causes of voice disorders.  

In summary, it’s important to understand some of the physiology of speech to know how these factors may affect you. Although I’ve removed a lot of heavy medical jargon from this explanation, I think understanding the function of it all and how it applies to your life and personal goals is the most important. 

To speak with one of the speech-language pathologists at Well Said: Toronto Speech Therapy, schedule an initial consultation by clicking the link below or calling (647) 795-5277.