Most singing teachers agree that both males and females have “head voice” as part of their sound. This term applies to the way the vocal cords vibrate and work when we sing high notes. I will go into the mechanics of the vocal cords in another article and in my courses, but for now let’s just understand that two strips of membrane in our larynx (adam’s apple) we call vocal cords vibrate against each other, turning air from our lungs into sound. For lower sounds (the chest voice) the full length or the cords is used for the action. Since higher sounds require smaller, shorter or thinner vibrations (think how a harp looks) the vocal cords must change in shape and size in order to make high notes.
As we sing higher notes our two vocal cords move closer together and begin to do what is called the “zipper effect”. Higher notes require a smaller opening for the air to go through, so a small miracle occurs as the cord begin to “zip” up, leaving a smaller and smaller opening. (Think of what a clothing zipper looks like as it zips up.)
So, when you think about it, it should take less air pressure to sing the high notes than the low ones, and it does. For low notes there is a big opening between the cords where you can pass a lot of air through without a lot of stress. And the high notes require a smaller opening between the cords. This smaller opening allows less air to pass through without stress. When we try to push too much air pressure (volume) through the cords for higher notes we cause them to work too hard resisting the extra air. This produces an overly-fat, amateurish sound which sounds forced and difficult.
When we sing higher we “feel” we must work harder to get those notes out. In fact, we need to back off some, feel the sound higher in our head, letting it thin like the higher notes of the piano or guitar.
Try singing a sweeping continuous “ah” or “uh” vowel, starting at your lowest note and “sweeping” or sliding the continuous sound up to your highest notes. Notice that you’ll probably reach a point when it seems you can go no higher. Lighten your sound there and begin to let it thin and feel higher in your head. Guys, if you go into the falsetto that’s OK for now. Let you voice do what it needs to do. Girls you’ll probably need to move into your head voice at some point. That’s ok. Just keep going, trying not to strain.
Do this exercise often, paying attention to how the higher notes feel. Are you pushing and straining, or are you just letting it sweep on up?