The following is an article I wrote in response to several bloggers arguing that the vocal cords CANNOT be manually or consciously pulled together, and that it is only the Bernoulli effect that pulls the back of the vocal cords together. Respectfully, I submit that they are wrong.
“The Bernoulli effect is absolutely what is involved in the production of tone at the vocal cord (or vocal fold) level. In fact, it is the cause of the sound of our speaking and singing voices (also known as phonation). As the air flows (from the lungs) across the cords, the vocal cords are pulled together, then the little bit of pressure built up is released, and the process starts over again. This releases sound waves (up to hundred of times per second) which we use when speaking or singing.
However, this effect CANNOT happen without the back of the cords FIRST being pulled close together (adduction) so that the cords are close enough to each other for the airflow to “suck” the cords together, beginning the vibration. The Bernoulli effect will not take effect until and unless the back of the cords are somewhat approximated (brought close together via adduction), otherwise we would phonate (make a sound at the vocal cord level such as in speech or singing) EVERY TIME WE ASPIRATE, breathing in or out. We have to bring them together to ALLOW the Bernoulli effect to take effect, creating sound. Usually we do this without thinking because we do it so often.
Many will say that one cannot consciously or mechanically bring the back of the cords together. They are wrong. We first “stumble” into it immediately after birth when we start screaming, but we can also consciously activate the cords pulling together. Of course, without proper airflow, bringing the cords together does nothing to produce any usable sound.
One such way to pull the vocal cords together in back is to make a vocal “fry”
or creaky or scratchy sound. When making these sounds, however, the airflow across the cords is somewhat constricted because there is typically TOO MUCH
pulling of the back of the cords together, and TOO LITTLE
air release across the cords, causing the fry or scratchy sound. This technique is typically used when a singer is releasing too much air across the cords, generally caused because the cords are NOT
being approximated and then stabilized by the muscles at the cord level.
These sounds are only meant to help a singer get a feel for controlling adduction while singing. When balanced properly, we don’t have to think about it, such as in the case of speech. The problem? We typically start to intrusively upset the balance of air and vocal chord adduction when using our singing voices because we try to make tones our ears like, instead of tones that are natural to our instruments. For instance, we don’t typically try to control the tone quality of our speaking voices. When speaking, we don’t really give it a thought, but when we sing we’ll often try to produce specific tone qualities that aren’t necessarily natural to our own “instruments”.
Bottom line? Yes, the back of the cords can be manually adducted, but this shouldn’t be something we HAVE to think about unless we are doing something funky to mess with the vocal process that we already experience from our speech voices.
There’s much more on this topic that I could address (to the absolute boredom of most, though quite interesting to those of us sharing a sick fascination with such things), but I’ll bore you no further! :-)”