Dr Gordon Soo, The ENTific Centre
Humans are social beings. We communicate with others using our voice as well as body language. So it naturally becomes a problem when we lose our voice.
We make our voice in our larynx. Here sit two ligaments called vocal cords, that are joined together in the front and sit apart at the back, like an open “V”. The vocal cords are covered with a soft mucosa lining, and lie horizontally immediately above our windpipe, acting as two guards protecting our airway.
So how do these two vocal cords make a voice? We need two things to occur for sound to be made. First the two vocal cords are brought together by a muscle, and at the same time, air from our lung is expelled through these closed cords. The air passing through our cords cause the mucosa covering to vibrate, and hence a sound (voice) is made. The pitch of this sound, our voice, is changed by other muscles tightening or relaxing the tension of the vocal ligaments. When the vocal ligaments are tightened, the voice becomes higher pitched, like when we strum a tightly stretched guitar string to create a higher note. For a lower tone sound, the tension is reduced, and a lower, more bass voice is produced. The voice of children, adult males and adult females also vary due to the size of the vocal cords and the “laryngeal” box that it sits in. A shorter vocal cord in a smaller box as in children produce a shriller, high tone voice whilst at the other extreme, a longer vocal cord in a bigger box of an adult male produces a deeper voice. Here the analogy is that of a child ukulele as compared to an adult double bass. The female adult voice is somewhere in between. So that is how the voice is made. Speech and language which strings sounds together to form words is different. Speech that form words of what we want to say, in the form of phonetics as well as the tone in tonal languages like Putonghua and Cantonese, comes from movements of our tongue above our voice box.>
So how do we lose our voice? The commonest cause is an acute inflammation of our larynx (acute laryngitis) e.g. when we catch the flu. The lining of the vocal cords become swollen, inflamed and stiff and the inflammation causes pain when we try to speak. As air passes through the cords, the vibration is impaired. Making a sound is difficult as well as painful, and the voice changes to a very hoarse rasp or total loss altogether.
Another way that voice production can be impaired is if there is a growth on a vocal cord that prevents both the vocal cords from coming together perfectly. Conditions that could do this are e.g. cancer of the vocal cords commonly seen in smokers. These growths tents open the gap between the cords, and allows air to leak through the gap, making voice production inefficient at best, and sometimes impossible at worst.
The ultimate voice loss occurs when the vocal cords cannot come together. This is definitely an uncommon condition. We need both vocal cords to vibrate to make a sound. When one of the vocal cords cannot be drawn close, the gap between the vocal cord is too wide for turbulence of the air, and therefore sound, to made by the passing air. It is the same as when we try to whistle. We can only make a whistle with “closed” lips and not an “open” mouth. Here the reasons why a cord cannot “close” is usually due to damage to the nerve that supplies the “closing” muscle of that vocal cord.
To lose one’s voice is not unusual at all and most voices recover very quickly. However, a persistent hoarse voice or loss of voice for more than three weeks is not normal. If this continues, further medical attention for a diagnosis would normally be advised.