How does your voice work?

We use our voices every single day to talk, sing, or yell— have you ever wondered how our voices work?

Voice production has three parts. First, our respiratory system is used to exhale air, which acts as the “fuel” of our voice. Second, the air passes through muscles in our throat which vibrate and produce sound. Lastly, the shape of our respiratory tract forms that sound into our voice.

The respiratory system includes the lungs, chest muscles, diaphragm, rib cage, and windpipe. When someone is about to talk, the first thing they do is inhale using their respiratory system. To do this, the diaphragm lowers and the rib cage expands which draws air into the lungs. People speak on their exhale, when the diaphragm relaxes and moves upward, causing air to move up and out of the lungs. The flow of air moving up through the windpipe is what powers the voice. Try to talk for as long as you can without breathing in again -- you’ll notice that when you can’t exhale any more air, you can’t speak any more words!

Exhaled air passes up through the windpipe and into the larynx, or “voice box.” Inside the larynx are vocal folds or “vocal cords,” which are two bands of muscle. When inhaling, the vocal folds are open to allow air to pass through, but when you start to speak on an exhale, the vocal folds close and start to vibrate, which produces sound. Pitch, or how high or low your voice sounds, is determined by how fast the vocal folds vibrate.

On its own, this would produce a buzzing sound that wouldn’t seem much like a human voice. That’s where “resonance” comes into play. The sound waves from the vocal folds bounce off of the structures of the throat, nasal passages, sinuses, and mouth. The length and shape of those structures forms the sound into a human voice. To speak any language, you then use your tongue, teeth, and lips to form the sound into words.

Even though we don’t have to think about it much, every day we use all of these structures to speak!