The voice is a musical instrument, just like a guitar or violin. But rather than wood and steel, we have muscle, ligament and tissue. 

Knowledge of the parts and function of your instrument is essential for all musicians. Understanding how your voice works can help you gain control of your voice and guide you to successfully eliminate vocal issues.


Where Are the Vocal Cords?

The Larynx-min

The vocal cords are located at the top of your windpipe or trachea. The cords are housed in your larynx (also called the "voice box"), which is the bump in the front of your neck that goes up and down when you swallow.

Note: "vocal cords" and "vocal folds" are used interchangeably in the singing world. While "vocal folds" is the more proper term, "vocal cords" is more commonly used. You may occasionally see "cords" spelled as "chords" - this is considered incorrect by most voice professionals.

The thyroid cartilage protects the vocal folds and appears as the "bump" or Adam's Apple in the middle of the neck. The Adam's Apple is more pronounced in men because of the protrusion of longer vocal folds.

The folds sit over the windpipe and open and close from the back, looking like a V in the open position.

illustration of a larynx

Note "Abducted" means the vocal folds are open - "adducted" means they are together and closed.  

What Are They Made Of?

a woman singing

Here's where things get interesting. Although many people try and describe the vocal folds in terms of a stringed instrument (such as the guitar), the folds' makeup is very different from a steel or nylon string.

The vocal cords are made up of three basic elements. The first layer is a length of ligament, which is where the term “cord” comes from.

The next layer is muscle that runs the length of the cord. This muscle is called the thyroarytenoid because of where it attaches on either side. We will call it the TA muscle for short.

Musculusthyreoarytenoideus

Finally, there is a layer of soft mucosal tissue, which covers the cords. The tissue appears as if folded over, hence the name "vocal folds." This soft tissue is necessary to allow the cords to vibrate and create sound waves.

Making Sound

a woman singing

The folds are open and apart when breathing. When you phonate (make sound), the cords are brought together over the top of the trachea or windpipe.

Now when air is blown through the closed folds they vibrate and make sound, much like the buzzing of a trumpet player's lips.

The degree to which the vocal folds close is important as not enough closure gives a weak, breathy sound, and too much closure creates strain and possible vocal damage.

I often have students do the following simple exercise to experience different degrees of vocal cord closure:

First, give a sigh – that is too little closure for most singing and practicing.

Now grunt as if lifting something heavy – that is too much cord closure. The muscles are pressing together too intensely.

Finally, say “mmmm” as if you are eating your favorite food. That should give you a better sense of proper medium-level vocal cord closure.

Here is a video of what the vocal folds look like when talking and singing. This method uses a strobe light to record the folds in slow motion. They are actually vibrating much faster.

Producing Pitch

The vocal cords are about the size of your thumbnail, contain no keys, tuning pegs, valves, multiple strings, or any of the other devices found in musical instruments, yet they can cover three octaves and more of range.

The cords can do this because of the interplay between the muscles and the ligament (cord).

In your lower register, you mainly change pitch by increasing or decreasing tension in the TA muscles (the muscles that run the vocal cords' length). The vocal cords are short and thick in these lower notes, with the TA muscles doing most of the work. 

As you raise pitch into your upper register, a new group of muscles becomes involved. These are called the cricothyroid muscles or CT for short.

a illstration of larynx

The CT muscles are attached to the front of the thyroid cartilage and pull the cartilage forward and slightly down. Since the folds are attached to the back of the cartilage, this action pulls and stretches the vocal folds.

The CT muscles stretch the cords, making them longer and thinner. The vocal ligament also increases in tension, raising the pitch. This is just like stretching a rubber band.

a woman stretching a rubber band

If you are a musician, you may be thinking if the cords are longer in head voice (the upper register), they should produce a lower note.

Yes, a longer string normally produces a lower note; however, the vocal folds more than compensate for this lengthening by becoming thinner and adding more tension. This gives us the ability to sing very high notes.

To reiterate: the vocal cords are short and thick in chest (or lower register) and long and thin in head (or upper register).

Muscle Interplay

tug of war-min

The relationship between the TA and CT muscles is significant in singing. If you engage too much TA tension when trying to sing higher, your voice will feel heavy and unable to reach the pitch. If you relax the TA too much and the CT or stretching muscles engage too strongly, you will flip to a light falsetto.

The key is to have these two groups of opposing muscles in a happy balance, the tensions between them dialed in for each pitch.

Much of your training as a singer will involve balancing this muscular tension.

Think of the opposing muscles (the TA and CT) as involved in a game of tug-of-war, with the TA team being much bigger and stronger.

The TA muscles (within the vocal folds) tend to be stronger and more actively engaged in the beginning singer. The TA muscles will over-squeeze and jam up the voice as you go higher, only to suddenly let go and cause the singer to crack and flip into a falsetto.

Training Muscle Balance

an illustration of a baton

Even advanced singers deal with the TA muscles wanting to over-engage. This is why we go through a series of warmups, to not only stretch the ligaments of the vocal folds but to encourage the TA muscles to give over to the stretching CT muscles.

The transfer from TA to CT is much like the handing of a baton in a relay race. A smooth transfer is an important part of running a successful race.

I highly encourage my students to warm up with a straw. The back-pressure created by vocalizing through a straw helps the TA muscles relax enough to allow the CT muscles to do their job effectively.

One of the major problem areas for singers is the transition between their lower register (chest voice) and their upper register (head voice).

This transition area is often called the "vocal break" because it is where the voice will tend to crack and struggle. The transfer from TA to CT occurs in this problem area.

The ability to hand over smoothly from the TA to CT muscles is vital in smoothing the vocal break and creating a seamless singing voice.

If you take voice lessons, your teacher will spend a large amount of time helping you smooth muscle transfer and help eliminate the vocal break.

Exercises

When learning to move between your lower and upper register, I recommend you start singing lighter as a heavier sound can over-engage the TA muscles.

Here is an exercise from my book, Beginning Singing, that can help you smoothly move between your registers.

Vocal Issues

SU-Design-1610643039-min

Improper balance and overuse of the voice can lead to chronic issues in singers and professional voice users. 

One of the main problems is nodules. When you use your voice with too much intensity or try to sing higher notes with too much TA involvement, you are slamming your vocal cords together hundreds of times per second.

This stress to the tissue of the vocal folds can lead to the formation of callouses, just like on your hands.

We call these vocal callouses "nodules," and while having these hardened bumps of skin on the palms of your hand is not usually an issue, these bumps create terrible problems for singers.

Nodules prohibit your vocal folds from closing completely. Symptoms include weak or breathy singing and restricted range, especially in the upper notes.

If you are dealing with hoarseness for more than a week (and you're not sick) or if your range becomes consistently diminished, I recommend you seek out a skilled voice doctor.

On a side note: common sense health habits such as limiting alcohol consumption and not smoking (or vaping, sorry) also lead to a healthier voice.

As in all things singing - good technique and healthy habits can help you avoid most vocal issues.

Take care of your voice, and you can enjoy singing for a lifetime.