Vocal Cords – What Singers Should Know
The vocal cords and how they function are often misunderstood by the singer (even some voice teachers are unsure of exactly what is happening). I believe the more you know about your instrument, the better singer and teacher you can become.
A basic understanding of the vocal cords and how they make pitch can help you more precisely analyze imbalances and construct more efficient practice routines.
Note that although the proper term is “vocal folds” we will be using the more popular “vocal cords.”
Vocal Cords – Where Are They?
The vocal cords are located at the top of your windpipe or trachea. They are housed in your larynx, which is the bump in the front of your neck that goes up and down when you swallow.
The cartilage that protects the vocal cords appears as the Adam’s Apple in a man. The vocal cords sit over the windpipe and open and close from the back, looking like a V in the open position (see picture above).
Vocal Cords – What Are They Made Of?
Here’s where things get interesting. Although many people try and describe the vocal cords in terms of a stringed instrument (such as the guitar) the make-up of the vocal cords is very different from a steel or nylon guitar 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 vocal cord. This muscle is called the thyroarytenoid muscle because of where it attaches on either side. We will call it the TA muscle for short.
Finally there is a layer of soft mucosal tissue, which covers the cords. It appears as if it is folded over, hence the term “vocal folds.” This soft tissue is necessary in order to create the buzzing sound waves.
Vocal Cords – How They Make Sound
The vocal cords are open when breathing, so they are not producing sound. You have muscles in the back that bring the cords together.
Now when air is blow through them they vibrate and make sound, much like the buzzing of a trumpet player’s lips.
The degree to which the vocal cords 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 the vocal cords together too intensely.
Finally, say “mmmmm” as if you are eating your favorite food. That should give you a better sense of proper medium-level vocal cord closure.
Vocal Cords – How They Make 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 four octaves and more of range.
The vocal cords are able to 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 length of the vocal cords). The vocal cords are short and thick in these lower notes with the TA muscles doing most of the work. Note: some people believe the cords are longer in lower or chest voice, this is incorrect.
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.
The CT muscles stretch the cords, making them longer and thinner. The vocal ligament also increases tension, raising the pitch. This is just like stretching a rubber band – it will increase in tension and pitch.
Some argue that if the cords are longer in head voice or the upper register they should produce a lower note, therefore they must be shorter. This is not true.
Yes, a longer string produces a lower note, however the vocal cords 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).
Click to see a video of the vocal cords changing pitch.
Vocal Cords – Muscle Interplay
The relationship between the TA and CT muscles is very important in singing. If you engage too much TA tension when trying to sing higher your voice will lock up. If you relax the TA too much and the CT or stretching muscles engage too strongly you will flip to a falsetto.
The key is to have these two groups of opposing muscles in happy balance, the tensions between them dialed in for each pitch.
This of course takes time and is part of good vocal training.
Knowledge of your instrument and the vocal cords is a good start in becoming a great singer.