According to the National Institute on Deafness and Other Communication Disorders (NIDCD), an estimate number of 7.5 million people in the United States alone have trouble using their voices. What about other communication disorders related to voice, speech, and language? The NIDCD has compiled the latest set of statistical data to illustrate the situation of deafness and communication problems in the United States, as follows.
Voice
- Spasmodic dysphonia, a voice disorder caused by involuntary movements of one or more muscles of the larynx (voice box), can affect anyone. The first signs of this disorder are found most often in individuals between 30 and 50 years of age. More women than men appear to be affected.
- Laryngeal papillomatosis is a rare disease consisting of tumors that grow inside the larynx, vocal folds, or the air passages leading from the nose into the lungs. It is caused by the human papilloma virus (HPV). Between 60 and 80 percent of laryngeal papillomatosis cases occur in children, usually before the age of three.
Speech
- The prevalence of speech sound disorders in young children is 8 to 9 percent. By the first grade, roughly 5 percent of children have noticeable speech disorders; the majority of these speech disorders have no known cause.
- By the time they are six months old, infants usually babble or produce repetitive syllables such as "ba, ba, ba" or "da, da, da." Babbling soon turns into a kind of nonsense speech jargon that often has the tone and cadence of human speech, but does not contain real words. By the end of their first year, most children have mastered the ability to say a few simple words. By 18 months of age, most children can say 8 to 10 words. By age 2, most put words together in crude sentences such as "more milk." At ages 3, 4, and 5, a child's vocabulary rapidly increases, and he or she begins to master the rules of language.
- It is estimated that more than 3 million Americans stutter. Stuttering can affect individuals of all ages, but occurs most frequently in young children between the ages of 2 and 6. Boys are 3 times more likely than girls to stutter. Most children, however, outgrow their stuttering, and it is estimated that fewer than 1 percent of adults stutter.
Language
- Between 6 and 8 million people in the U.S. have some form of language impairment.
- Research suggests that the first 6 months of life are the most crucial to a child's development of language skills. For a person to become fully competent in any language, exposure must begin as early as possible, preferably before school age.
- Anyone can acquire aphasia (a loss of the ability to use or understand language), but most people who have aphasia are in their middle to late years. Men and women are equally affected. It is estimated that approximately 80,000 individuals acquire aphasia each year. About 1 million persons in the U.S. currently have aphasia
Source: Compiled by NIDCD based on scientific publications.
