The Prevalence of Voice Disorders
In the United States, voice disorders affect approximately 25 million people, and yet there are less than 80,000 patient visits annually to a voice specialist. For this population, voice disorders are not just a mere annoyance. Voice disorders may have severe social, psychological, professional, and economic consequences. In particular, the professional and economic impacts will continue to increase as the United States’ economy continues to shift from manufacturing to a service/information base. As a result, by 2010, the portion of the population that relies on its voice for their profession will grow five times faster than those who do not need their voices for their work.
Since approximately 1% of the American population has a voice disorder, the prevalence of voice disorders is higher than other well-known diseases as compared below:
Table 1: Relative Prevalence of Well-Known Diseases
|Disease||Per 1,000 Population|
Additionally, as many as 50% of the American population has reflux disease, a condition caused by the backflow of stomach contents into the esophagus and/or throat. Reflux is one of the most commonly under-diagnosed and under-treated causes of voice problems, and is an important focus of contemporary laryngology. Until relatively recently, many voice disorder patients went untreated, but today, with advances in diagnosis and treatment, that has changed.
Levels of Vocal Usage
The success of treating patients with voice disorders depends to a great extent upon accurate diagnosis and identification of the vocal needs of each patient within the context of the patient’s professional and social needs and obligations. The same voice disorder may have profoundly different impact on two different patients, depending on their professions. There are four levels of vocal usage, based upon a hierarchy of vocal use, performance, and need:
I. The Elite Vocal Performer. Level I, is a person for whom even a slight aberration of voice may have dire consequences. Most singers and actors are in this group; the opera singer is the quintessential level I performer.
II. The Professional Voice Use. Level II, is a person for whom a moderate vocal problem might prevent adequate job performance. This group includes most clergy, teachers, lecturers, receptionists, etc.
III. The Non-Vocal Professional. Level III, is a person for whom a severe vocal problem would prevent adequate job performance. This group includes lawyers, physicians, businessmen, business women, etc.
IV. The Non-Vocal Non-Professional. Level IV, is a person for whom vocal quality is not a prerequisite for adequate job performance. This group includes clerks, laborers, and so forth. Although persons in this group may suffer very significant social liability from a voice disorder, they are not prevented from doing their work.
While this classification of levels of vocal usage is helpful in examining the question of who gets voice disorders, it does not have any implications for the overall social and psychological impact of impaired communication that may be suffered by any person with a voice disorder. In the author’s experience, the breakdown of her voice patients is: about half are level I and II professionals and almost half are level III patients.
Professional vocalists, especially singers, are the first to seek medical attention if something happens that adversely affects the voice. These are important patients because when a voice disorder strikes a well-known vocalist, it may prevent an adequate performance or even force cancellation of performances. Obviously, concert promoters, support staff, and the public are also adversely impacted. Thus, a voice disorder may have profound financial and professional implications for the singer’s career and may damage the singer’s reputation.
Most commonly, the voice problems of vocal performers are acute “emergencies” caused by upper respiratory infection, such as a cold, or they are stress-related. The latter are most commonly due to voice strain and/or extraesophageal reflux (the back flow of stomach contents into the voice box). The treatment for each condition must be individualized.
Other professional voice users (levels II and III) may suffer similar emergencies; however, more commonly, the voice problems in these groups are chronic and intermittent. For non-vocal non-professionals, the type of voice problems may be similar, but level IV patients usually do not seek medical attention until the problem is both chronic and severe. However, any level (I-IV) patient may be just as severely affected from a social and a psychological point of view as any other patient.
The Multiple Causes of Voice Disorders
In most cases, voice disorders are multifactorial (that is they have more than one cause.) It’s almost as though several things wrong need to occur before voice decompensation occurs; see “vocal decompensation.”
The most common problems that affect the voice and larynx are laryngopharyngeal reflux (the backflow stomach contents into the throat) that may be completely sound occurring without heartburn or digestive symptoms, vocal fold weakness (partial paralysis or the effects of aging and “Bell’s palsy of the throat”), and voice misuse abuse and overuse syndromes.
Lesions (growths) occurring on the vocal folds usually result from vocal fold weakness, laryngopharyngeal reflux, and/or vocal fold bowing (weakness paresis). The table below shows the results of a study done on 200 voice disorder patients by Dr. Jamie Koufman, Director of the Voice Institute of New York.
It can be seen that approximately 75% of patients have laryngopharyngeal reflux and 50% have vocal weakness or some other neurological problem that affects the voice while 1 out of 5 (20%) have a vocal fold growth of some kind, and 90% have abnormal laryngeal biomechanics (meaning they are having to use compensatory mechanisms such as extra work, to achieve vocal fold closure. Table 2 below shows the distribution.
Table 2: Results of the Voice Disorders Etiology (Causes) Study
|Inflammatory disease (e.g., reflux and respiratory infections)||75%|
|Neuromuscular disease (e.g., paralysis, bowing, thinning, SD)||50%|
|Neoplastic growths (e.g., polyps, nodules, papillomas, cysts)||20%|
|Hyperkinetic laryngeal biomechanics (e.g., muscle tension)||90%|
* This means that the average voice disorder patient has 2.35 underlying problems contributing to their voice disorder.
Because so often voice disorders are inappropriately and incorrectly diagnosed, the Voice Institute of New York prides itself on providing precision diagnostics. These include videostroboscopy, laryngeal electromyography, acoustical measurement, reflux testing, and analysis of oropharyngeal secretions (sputum and spit) for specific diseases.
Most people who have voice disorders have Laryngopharyngeal reflux, vocal fold paresis, or both (Note: Paresis is synonymous with partial paralysis, weakness, trophy, and bowing. Often these conditions, even when appropriately diagnosed, are undertreated. In truth, effective treatment works, and usually the voice can be restored.