Module 2 Lesson 3: Demystifying Vocal Cords: The Singer's Essential Guide
Transcription
In the last lesson, you learned all about the energy source we use for singing — the breath.
So what’s the second thing that an acoustic instrument needs to make sound?
That’s right! Something that vibrates.
In this lesson, we’ll take a look at the incredible, tiny, powerful yet fragile thing that vibrates in your neck called…
The Vocal Cords
Here’s an illustration of your vocal cords. What you’re seeing is the view from above looking down into the windpipe or trachea.
The front of the neck is at the top, and the back of the neck is at the bottom.
The vocal cords (or vocal folds — those two terms are synonymous) are strung from front to back.
The illustration on the left shows the vocal folds in an open position. This is what they look like when you’re inhaling or exhaling.
On the right, you can see what they look like when you’re singing or speaking. To the naked eye, the vocal folds appear to be tightly closed. Actually, there are tiny puffs of air going through them, causing them to vibrate. They vibrate really fast at about 125 times per SECOND.
Vocal Fold Vibration
In this series of photographs, you can see that cycle from start to finish. Again, this is all happening 125 times per second. No wonder we can’t see them with the naked eye!
[Back to headshot]
So, when I say that the vocal cords need to be tightly closed, this rapid cycle of vibration is what I’m talking about.
The space between the vocal cords is called the glottis, and it has to be closed to make a sound. If the vocal folds are completely open, you won’t hear anything but the sound of an out-breath.
[BREATH EXAMPLE]
If they’re closed, but not tightly enough, you’ll hear a breathy tone.
[SINGING EXAMPLE]
You’ll also lose air pressure in the lungs. This build-up of air in the lungs is called intrathoracic pressure.
It’s kind of like a garden hose. If you have a hose and there’s nothing on the end, the water just gushes out without any pressure behind it. But, if you put your thumb over the opening, back pressure is created, and the water that’s coming out of the hose has more intensity.
So, we need to get the glottis closed. And there are two ways to do it.
The first way is by using your swallowing muscles. You swallow approximately 2,000 times per day, so these muscles get quite a workout. However, the swallowing muscles are small, and they tire out quickly — especially if you’re singing high, loud, or for a long time.
The Phrenic Nerve
The more efficient way to get those vocal cords closed is through the phrenic nerve. The phrenic nerve is a reflex nerve, like the nerve in your knee. You know when you go to the doctor, and he or she taps on your knee and your foot jumps? That’s a reflex nerve in action. It’s like a light switch. You turn it on at its origin point, and the nerve lights up and moves a muscle elsewhere.
The origin of the phrenic nerve is in the diaphragm. When contacted, it sends a message up through the spine, to the vocal folds, signaling them to close.
The Thoracic Cavity
So, let’s recap. You’ve expanded the tummy, and the air gets sucked in. A nano-second before you start to sing, you start lifting in and up, the abdominal bulk pushes against the diaphragm, stimulates the phrenic nerve, which then sends a message up to the vocal folds, and they close.
As you sing, you continue to lift in and up, keeping the rib cage expanded. The diaphragm remains taut, like a drum, and the phrenic nerve continues to be stimulated. This is how you create support.
It’s a beautiful system, right? I was so excited when I learned this.
I developed nodules because the muscles that adduct (or close) the vocal cords weren’t strong enough to withstand the amount of air pressure that I was using to sing high, and loud, for hours at a time. I also wasn’t lifting in and up, but pushing out and down, creating locked abdominal muscles.
The result was a lot of tension in my body, the phrenic nerve wasn’t being stimulated, and the swallowing muscles jumped in to try and run my voice. They would then tire out, and the glottis wouldn’t close tightly enough. The vocal cords started to rub up against each other. And what happens when tissue rubs up against tissue over time? That’s right. It tries to protect itself by creating a callous.
When I learned about the phrenic nerve system, it gave me hope. Every night at the gig, when I felt pain, it would remind me to lift in and up, just like in the vocal exercises I was practicing at home. I knew I was doing it right when the pain started to go away. About a year and a half later, the calluses were no longer needed, and they sloughed off.
So let’s take a moment here to talk about the abdominal muscles and how to use them when you lift.
The Abdominal Muscles
You have four sets of abdominal muscles: the transversus abdominus, internal and external obliques, and the rectus abdominus muscle, which is the one you use to stand and walk. Muscle is made of fast-twitch and slow-twitch muscle fibers. When you initiate the lift of your tummy, the fast-twitch muscle fibers activate. When you continue the lift, the slow-twitch fibers come into play.
It’s important how you use these muscles when you lift in and up. Everybody’s different. Some people are wound tight, others are more phlegmatic. If a student was wound tight, I worked with them to get the abs to relax so they could be more flexible. With students who were a bit too relaxed or had weaker abs, we worked on creating more strength and tension in the muscle.
So let’s talk about tension. Tension isn’t a bad thing. No matter what kind of physical activity you’re engaged in, you have some in your body. The important thing is to have the right amount of tension. Take the simple act of picking up a pencil. Without enough pressure in the fingers, it falls out of your hand. Too much stress in your grip and you’ve got a lot of wasted energy, and no flexibility for using the pencil to write.
It takes a lot of experimentation and practice to find just the right amount of tension in movement. As small children, we try and fail to pick up objects many, many times before we eventually succeed. The same process happens in any physical activity we engage in. Picking up a pencil, hitting a tennis ball, running, walking, or singing — all of these activities require coordination of muscles, and that coordination develops over time.
So, when you’re lifting in and up with those abs, the right amount of tension is key. Too much and the abs will lock. Not enough, and you won’t have the kind of support needed to get that phrenic nerve activated, the glottis closed, and that intrathoracic pressure going.
If breathing and support aren’t an issue in your singing — don’t make them so! As they say, don’t fix it if it ain’t broke. If you’re a natural singer, keep doing what you’re doing. But make sure you understand how your instrument works so that if someday things fall apart, you’ll have a better chance of putting them back together again.
On the other hand, if you're having issues with breathing and support, work with a voice teacher who has the knowledge and skills to help you find where you are too tight or too loose in your vocal technique. We’ll talk more about voice teachers at the end of this module, and how to pick one that’s right for you.
Next, we have the final piece of the puzzle — the third element that an acoustic instrument needs to make a sound — a resonator.
