Each time you scream at your kids to “stop it!” or channel Miley Cyrus at a karaoke session, some very thin and small tissues are hard at work so you can be heard.

Your vocal cords or vocal folds – along with your throat, nose and mouth acting as a resonating chamber – are what determine your voice’s pitch (how high or low you sound), amplitude (how loud or soft your natural voice is) and whether you sound like Mickey Mouse or Morgan Freeman.

Your voice’s uniqueness (yes, like your thumbprints) can also be affected by emotions, like the higher-pitched voice you may unconsciously use to interact with a puppy or baby. Interestingly, hormones may play a part in how you sound as well; University of California researchers found that hormonal changes during a woman’s most fertile part of her menstrual cycle can cause her pitch to rise, perhaps because women with higher voices are often perceived as more attractive.

Even if you don’t use your voice for a living the way teachers, presenters, singers and those working in sales do, it still pays to take good care of your vocal cords – and not only when you have a sore throat or lose your voice just before an important presentation. Here’s a look at what vocal cords are and how to spot trouble.

WHAT ARE VOCAL CORDS?

The words “vocal cords” may give off the wrong impression as they aren’t like the strings on a guitar that vibrate when plucked.

At just 12mm to 24mm long and 3mm to 5mm thick, your vocal cords are actually two ivory-coloured bands of tissue in your voice box or larynx (that protruding, bony bit in your throat).

Small muscles surrounding your vocal cords snap the cords open and close, “causing them to vibrate rapidly and produce sound” when air passes through them, according to Dr Charn Tze Choong, the head and senior consultant with Sengkang General Hospital’s Department of Otolaryngology (ENT) - Head and Neck Surgery.

“These muscles that surround the vocal cords are divided into intrinsic and extrinsic muscles,” he continued. “Intrinsic muscles execute exquisite coordination to not just vibrate the cords, but also lengthen, tighten, slacken and perform minute changes to the cords’ thickness and tautness to change your voice’s amplitude and pitch.”

Extrinsic muscles, on the other hand, move the larynx as a whole and can also affect the pitch of the sound you produce.

Other than giving you a voice, vocal cords also prevent saliva, food and drink from entering the airway when you swallow, said Dr Charn.

WHY DO MEN HAVE DEEP VOICES AND ADAM’S APPLES?

The name “Adam’s apple” apparently comes from the biblical tale of that bite of apple that Adam took in the Garden of Eden. It supposedly got lodged in his throat, even to this day in the throats of his descendants.

The medical explanation doesn’t involve any fruit eating though. Before puberty, girls and boys have the same larynx sizes but around ages eight to 13 for girls, and nine to 14 for boys, the larynx starts to grow and develop cartilage to protect the vocal cords. That’s when the difference stars to show or shall we say, sound.

Owing to boys’ higher testosterone levels during puberty, their vocal cords get thicker and longer than girls’, giving rise to their deeper voices. “In males, the vocal cords take longer to vibrate, hence, lowering the frequency of vibrations per second and lowering the pitch,” said Dr Charn.

Male larynxes also grow larger to accommodate the bigger vocal cords, giving rise to the Adam’s apple that you see in men. And get this: Those with a larger Adam’s apple tend to have a deeper voice. Imagine the size of the late James Earl Jones’s larynx.

WHAT’S THE WORST THING YOU CAN DO TO YOUR VOCAL CORDS?

Screaming, yelling, coughing, repeatedly clearing the throat and overusing the voice can cause phonotrauma, which is trauma or physical stress to the delicate vocal cords, said Laura Chua, a senior principal speech therapist at Sengkang General Hospital.

“In the short term, there may be swelling of the vocal folds and mild changes in vocal quality. However, over time, repeated injury can lead to the development of vocal fold lesions or even scarring and more permanent hoarseness,” said Chua.

LOST YOUR VOICE OR SOUND HOARSE? IT COULD BE:

Vocal cord nodules: The most common causes are vocal cord nodules that result from voice overuse, said Dr Charn. “The nodules are sometimes named singers’ or teachers’ nodules as classically, they affect professions that use their voices the most intensively.”

What can happen is, the vocal folds swell and over time, the swollen spots harden like a callous. If the voice abuse continues, the spots can get larger and stiffer, and become nodules. Nodules are solid bumps and are non-cancerous but they can cause your voice to sound weak or hoarse.

Muscle tension dysphonia: This is another common cause of voice loss, said Chua. “It refers to excessive muscle tension in and around the larynx, resulting in hoarseness, vocal strain and discomfort while speaking.”

Chua said that muscle tension dysphonia can be caused by factors such as inefficient voice use, a throat infection, irritants such as acid reflux and increased vocal demand. “In some instances, it can be a reaction to stress and anxiety or an emotional life event.”

Vocal paralysis: When the nerve impulses to the larynx are disrupted, the vocal cord muscles become paralysed and are unable to open and close the vocal cords. In most cases, only one vocal cord is paralysed but it can already cause difficulties with speech, and significant issues with breathing and swallowing.

The possible causes can include nerve damage during surgery on the thyroid, throat or upper chest, viral infections such as COVID-19 and herpes, stroke, neurological conditions such as Parkinson’s disease and certain cancers.

Sore throat: When there is an infection caused by a cold virus, the voice box becomes congested with inflammatory white cells, said Dr Charn. “This congestion hinders the effective functioning of the vocal cords from opening and closing fully, leading to voice breaks, roughness, or loss of pitch during vocalisations.”

Age: Your skin isn’t the only organ that sags as you get older. “As one ages, the vocal cords lose their collagen matrix, becoming less full and plump,” said Dr Charn. “This can result in a tiny gap between closed cords, leading to voice weakness known as ‘asthenia of the voice’ and is diagnosed as presbyphonia or ageing voice.

WHAT ARE THE SYMPTOMS AND TREATMENTS?

Look out for voice changes, voice breaks, ineffective communication and an inability to sustain a normal conversation at any point in time, said Dr Charn. Get yourself to an ear, nose and throat (ENT) specialist to exclude other causes such as early cancer, and a speech therapist for voice therapy, he said.

The first line of treatment for many voice disorders, including vocal cord nodules and muscle tension dysphonia, is voice therapy, said Chua. It is a guided programme conducted by speech therapists and consists of:

Vocal hygiene: Reduce behaviours and lifestyle habits that may damage the voice, including staying hydrated, reducing acid reflux, and avoiding excessive loud talking.
Therapy exercises: Improve hoarseness and relieve symptoms associated with voice problems. The variety of techniques used can include posture adjustment, relaxation, breathing, airflow and resonant voice.

HOW DO YOU PROTECT YOUR VOCAL CORDS?

Taking a preventive approach is key, said Chua, who suggests these ways to care for your voice:

Drink plenty of water to hydrate the throat. A general guideline is to drink enough so that the urine is pale in colour.

Minimise the intake of food and drinks that can trigger acid reflux. Examples include spicy and fried foods, and caffeinated beverages. Acid reflux irritates the vocal folds and increases throat discomfort.

Schedule silence breaks to rest the voice. On days with heavy voice use, schedule quiet time during lunch break and in-between meetings.

Knowing your vocal limits such as your pitch, loudness and stamina – and stay within them. Avoid using your voice beyond what it can handle on a daily basis. Warm up your voice before rehearsals and performances, and give it ample time to rest thereafter.

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