YOUR HEALTH - MEDICINE 101

VOCAL CHORDS
Every time you open your mouth to speak, a tiny miracle happens right here in your voice box. A little bit of air and a lot of physiology produce the sound we humans know as speech.

The larynx or voice box, is a collection of tubing and fine muscles protected by plates of thick cartilage, such as the Adam’s Apple. The main function of the larynx is not speech but rather protection – when the larynx, is closed it prevents any food or drink from entering your lungs instead of your stomach. Your mother was right when she said not to talk with your mouth full.

Here’s a pig’s larynx – see the fold of muscle that blocks off and protects the lungs when you, or the pig, swallow.

But in the middle of the larynx two horizontal muscles come close together like this – their stiff edges are called vocal chords or folds. Here’s what they look like. Anatomically, these white edges of muscles are responsible for much of our success as a species – because they allow humans to communicate – to teach each other, to work together, to transmit information and emotion and even to entertain each other.

Here’s how it works. The muscles are strong and they stretch across the trachea, (one on each side), the windpipe carrying air up from the lungs. When we breathe out, these muscles just touch together, stopping the flow of air out of the lungs, then they quickly open and close again, producing a pulse or puff of vibration and that produces the sound. The opening and closing all happens very fast – about 120 times a second. Incredibly, we can control how fast this opening and closing happens and also the length and shape of the two muscle edges, the vocal chords.

If the muscles are thickened and they don’t touch properly, some air leaks past – that’s the hoarseness of laryngitis. If the edges of the muscles don’t touch at all, that lets lots of air rush by, producing a whisper.

Singers take these lowly muscles to great heights, training them to vibrate on command and using the rest of the throat as a resonator.

It really is an amazing system. We all have the same anatomy yet it allows such individual variation -- we can easily recognize the voice of a friend. I don’t know about you, but the whole thing leaves me – well – speechless.