How Does the Voice Work?
Last week I reviewed the very basic anatomy of the vocal tract. During that post, I promised a post about the physiology of the three subsystems of voicing. This post will give a bird’s eye view of these subsystems and how they function (physiology). By the end of this post, you should be able to provide a basic answer to the question: How does the voice work?
Disclaimer: While I am a speech pathologist, I am not your speech pathologist. The information provided below is my own experiences and opinions. If you have medical questions on a personal level, please seek guidance from your medical team.
The Three Subsystems
The three subsystems of voicing are: respiration, phonation, and resonation. We discussed the very basic anatomy of each of these systems in last week’s post. In case you missed it, you can read that post here. Now that we’re all caught up, let’s talk about how these subsystems work together.
Respiration
The diaphragm flattens, the pressure in the lungs lowers, and air flows into the lungs. This displaces the organs in the abdomen, and the abdomen expands out and away from the spine. The rib cage also swings up and out to allow air into the lungs. When we’re exercising, sometimes the shoulders rise to allow even more air exchange in the lungs, but for speaking and singing, the movement of the abdomen and lower rib cage is enough. Exhalation involves the opposite movement: the rib cage collapses, the abdominal muscles push against the viscera, pushing on the diaphragm, and thus, pushing air out of the lungs. This movement can be fast, slow, or somewhere in the middle. The air movement of exhalation provides power to the voice. Quicker airflow allows for increased loudness. Slower airflow is ideal for speaking and singing.
Phonation
Phonation occurs due to vibration of the vocal folds. The vocal folds sit right at the top of the trachea. The lateral cricoarytenoid and the interarytenoids bring the vocal folds close to each other. Then, the airflow coming up from the lungs, through the trachea sucks the vocal folds together because of the Bernoulli principle. This begins the vibratory cycle. (Aside: For fun experiments to demonstrate the Bernoulli principle, check out this pdf from NASA). The vibration of the vocal folds frequently occurs in short spurts when speaking because the voice turns on and off for voiced consonants and vowels vs. voiceless consonants. This is an AMAZING amount of coordination when you think about speech - perhaps even another post’s worth of information! The vocal folds vibrate more when singing because we tend to sing on vowels and, sometimes, voiced consonants. You can’t sing on a voiceless consonant like /k/! Try it - I dare you. It will become a /g/.
Resonation
If I took your vocal folds out of you body and placed them on a bench to blow air through them, they would buzz. It wouldn’t sound like your voice at all. What makes our voices sound like our voices are the resonating cavities that sit above the larynx. The major resonating cavities for our voices are: the mouth, throat, and nasal passages. These cavities are like the organ pipes of our voices. They filter out some frequencies and amplify others. The muscle patterns of these cavities can drastically change how our voices sound. If you close off the nose by raising the soft palate, your voice will become hyponasal. You can do the opposite by letting more air through the nose. The voice becomes hypernasal. See the companion YouTube video of this post (above) to hear a few other examples.
A Good Beginner’s Understanding
That’s the down and dirty answer to “How does the voice work?” Those three subsystems provide lots of different options for voicing. Future posts will explain some of these concepts in greater detail, but this explanation provides a good base for singers and professional voice users to better understand their instruments. Wanna learn more about how to care for your voice? Coinsider taking my vocal wellness course! Until next time, I wish you success on your wellness journey.