Dysphonia & Hoarseness of Voice
Anatomy of the voice box
The voice box or larynx is situated in the neck. At its top end it communicates with the throat, and at its lower end continues as the wind pipe (trachea). Within the voice box are 2 pale white bands called vocal cords or folds. Surrounding the voice box and attached to it are various muscles that move these vocal folds. Apart from producing voice, the larynx also protects the lower airway and lungs from contamination by food particles and other substances that pass through the throat.
How do we produce voice?
The voice box can be compared to a string instrument. The 2 vocal cords are like strings that move, stretch, and relax. These movements are brought about by muscles attached to the voice box. The lungs are the bellows that drive air through the vocal cords, and as they move this air stream is interrupted in various ways producing notes or voice. Resonance, which gives a person the characteristic voice, is added to these notes by the throat and nose.
What is dysphonia?
Dysphonia is an alteration of voice. Hoarseness is a type of dysphonia. Problems of the vocal cords or the resonating structures can all lead to dysphonia.
What causes dysphonia?
Swelling of the voice box or resonating structures can cause dysphonia. However, problems with the other participants in voice production (lungs – bellows, resonating structures – throat, nose) can also lead to dysphonia. Some common causes of dysphonia are listed below:
Inflammation of the voice box can arise due to an infection or injury. A viral cold is a typical example where the voice box is swollen and so are the vocal cords. Their movement produces a discordant note and dysphonia.
Injury to the voice box can occur due to excessive straining of the muscles that move our vocal cords. Vocal abuse is a term used to denote such an injury. Shouting, straining to produce voice when the larynx is inflamed can both lead to muscle strain.
Irritation of the voice box and vocal cord lining is seen in patients who smoke. Over a period of time these structures become swollen and produce a discordant note. Irritation can also lead to changes in the vocal cords that are indicative of cancer, and voice change or hoarseness is an early sign.
Vocal cord polyps, nodules, cysts
These are swellings localised to the vocal cords. They develop when the voice box is used in an inappropriate manner. They can be compared to the formation of a callus on the foot. Vocal misuse leads to certain areas of the vocal cords to thicken and form any of the conditions mentioned above.
When the bellows are affected, voice production is not optimal leading to dysphonia. This is seen in patients with asthma or chest infection.
Problems with the resonating structures
Common examples of this are a throat infection or rhinitis. Swelling of these structures leads to an alteration of voice quality and dysphonia.
How is dysphonia managed?
A good history and examination are essential to correct diagnosis. Flexible laryngoscopy is a vital part of the examination. In early cases voice care (see below) may be all that is required. Speech therapy forms an essential part of this treatment. Speech therapists assess your voice and provide you with general rules of voice care along with structured exercises to prevent vocal misuse.
If the flexible laryngoscopy shows the presence of a well defined swelling such as a polyp, it may need surgical removal. This procedure is called a microlaryngoscopy. As the name suggests the larynx is examined with the aid of a microscope to magnify the offending lesion and remove it without damaging the underlying fine vocal cords. It is performed under a general anaesthetic.
How can I take care of my voice box?
Here are some general rules that can be followed to look after your vocal apparatus:
Drink plenty of water to keep the vocal cords lubricated. 6-8 glasses/day is recommended. Avoid excessive intake of coffee, tea, or alcohol as these act as diuretics and can lead to a dry throat.
Practice good breathing techniques when singing or talking. Support your voice with deep breaths from the diaphragm, the wall that separates your chest and abdomen. Talking from the throat, without supporting breath, puts a great strain on the voice.
Do not misuse your voice. Shouting in noisy places can cause strain and voice problems. If you have to address a crowd or lecture, use a microphone, keep a glass of water, and take sips regularly.
If you are losing your voice, try to rest it as much as possible. Do not whisper as it adds to the strain on your vocal cords.