voice tracing

Causes of Voice Disorders


Laryngitis is a swelling of the vocal cords usually due to an infection. A viral infection (a “cold”) of the upper respiratory track is the most common cause for infection of the voice box. When the vocal cords swell in size, they vibrate differently, leading to hoarseness. The best treatment for this condition is to rest or reduce your voice use and stay well hydrated. Since most of these infections are caused by a virus, antibiotics are not effective. It is important to be cautious with your voice during an episode of laryngitis, because the swelling of the vocal cords increases the risk for serious injury such as blood in the vocal cords or formation of vocal cord nodules, polyp, or cysts.

Vocal Cord Lesions

Benign noncancerous growths on the vocal cords are caused by voice misuse or overuse and from trauma or injury to the vocal cords. These lesions (“bumps”) on the vocal cord(s) alter vocal cord vibration. This abnormal vibration results in hoarseness and a chronic change in one’s voice quality, including roughness, raspiness, and an increased effort to talk. The most common vocal cord lesions include vocal nodules also known as “singer’s nodes” or “nodes” which are similar to “calluses ” of the vocal cords. They typically occur on both vocal cords opposite each other. These lesions are usually treated with voice rest and speech therapy (to improve the speaking technique thus removing the trauma on the vocal cords). Vocal cord polyp(s) or cyst(s) are other common vocal cord lesionscaused by misuse, overuse, or trauma to the vocal cords and frequently require surgical removal after all nonsurgical treatment options (i.e., speech therapy) have failed.

Reflux Diseases

Reflux (backflow of gastric contents) into the throat of stomach acid can cause a variety of symptoms in the esophagus (swallowing tube) as well as in the throat. Hoarseness (chronic or intermittent), swallowing problems, a foreign body sensation, or throat pain are common symptoms of gastric acid irritation of the throat, called laryngopharyngeal reflux disease (LPRD).

Vocal Cord Paralysis

Hoarseness and other problems can occur related to problems between the nerves and muscles within the voice box or larynx. The most common condition is a paralysis or weakness of one or both vocal cords. Involvement of both vocal cords is rare and is usually manifested by noisy breathing or difficulty getting enough air while breathing or talking. However, one vocal cord can become paralyzed or severely weakened (paresis) after a viral infection of the throat, after surgery in the neck or cheek, or for unknown reasons.
The immobile or paralyzed vocal cord typically causes a soft, breathy, weak voice due to poor vocal cord closure. Most paralyzed vocal cords will recover on their own within several months. Surgical treatment is required if paralysis becomes permanent. Surgery for unilateral vocal cord paralysis involves positioning of the vocal cord to improve the vibration of the paralyzed vocal cord with the non-paralyzed vocal cord.

Stroke and other Diseases

Language impairment -- or aphasia -- occurs in more than a third of people who survive a stroke on the left side of their brain. Many recover within a few months after the stroke, but up to 60% still have language impairments more than six months after a stroke, a condition known as chronic aphasia.
A large percentage (89%) of people with Parkinson's disease have speech and voice symptoms, but only 3% to 4% of them receive speech treatment. Most people with Parkinsons have soft voices because the disease makes it harder to force the neccesary amount of air through the larynx or voice box to produce a normal speaking volume, and the vocal cords are often weakened and don't vibrate adequately to produce sound.


When cancer attacks the vocal cords, the voice changes in quality, assuming the characteristics of chronic hoarseness, roughness, or raspiness. These symptoms occur at an early stage in the development of the cancer.
Persistent hoarseness or change in the voice for longer than two to four weeks in a smoker should prompt evaluation by an otolaryngologist to determine if there is cancer of the larynx (voice box). Different treatment options for this cancer of the voice box include surgery, radiation therapy, and/or chemotherapy. When vocal cord cancer is found early, typically only surgery or radiation therapy is required, and the cure rate is high (greater than 90 percent).

Laryngeal cancer

Cancer of the larynx (the voice box including vocal chords and epiglottis) is a rare disease and the incidence varies from country to country. Laryngeal cancer accounts for less than 1% of all cancers. More than one hundred thousand new cases are reported worldwide each year, but the prognosis is usually good. This is because the larynx is sensitive even to very small changes, so it is normally discovered early. The cause of this cancer is not absolutely clear, although links with tobacco and alcohol have been established. However, both nonsmokers and nondrinkers have also been diagnosed with this form of cancer, so there does not seem to be a definite causal relationship.

Laryngeal cancers are treated by radiation- and chemo-therapies. If the tumor is too large, it will probably have to be removed by surgery. This type of surgery is referred to as a total laryngectomy and the patient is afterwards referred to as a laryngectomee. The laryngectomee breathes through an opening in the neck and has to rely on different devices for speech production.