November 18, 2011

Listen up! 1 in 5 Americans Has Hearing Loss

(Ivanhoe Newswire) -- Say what?! You heard right, nearly a fifth of all Americans 12 years or older have hearing loss so severe, it may make communication difficult. The findings suggest that many more people than previously thought are affected by this condition.

"This gives us the real scope of the problem for the first time and shows us how big of a problem hearing loss really is," said study leader Frank Lin, M.D., Ph.D., and assistant professor at the Johns Hopkins School of Medicine and Johns Hopkins Bloomberg School of Public Health.

Using the World Health Organization's definition for hearing loss - not being able to hear sounds of 25 decibels or less in the speech frequencies - Johns Hopkins researchers found that around 30 million Americans, more than 12 percent of the population, had hearing loss in both ears. The number jumped to around 48 million, more than 20 percent, for hearing loss in at least one ear.

These numbers exceed, by far, previous estimates of 21 to 29 million.

In addition, hearing loss prevalence was found to nearly double with every age decade. At any age, researchers found women and blacks were significantly less likely to suffer hearing loss.

The female hormone, estrogen, and the melanin pigment in darker skin may have a protective effect on the inner ear, Lin noted, adding that he and his colleagues plan to research those topics in future studies.

Researchers analyzed data from Americans 12 years of age and older whose hearing was tested during the National Health and Nutritional Examination Survey examinations from 2001 to 2008. The NHANES is a research program that has periodically gathered health data from thousands of Americans since 1971. It is thought to statistically mimic the population of the U.S. because it includes men and women of all races and ages, from cities scattered across the country.

The new numbers greatly inform the work researchers are doing on hearing loss and its consequences, which include cognitive decline, dementia and poor physical functioning, Lin said.

The study is thought to be the first nationally representative estimate of hearing loss. Several previous estimates focused on various cities, or populations such as children and elderly patients. However, no estimate successfully encompassed the entire U.S., explained Lin.

"I couldn't find a simple number of how common hearing loss is in the U.S., so we decided to develop our own," Lin was quoted as saying.

SOURCE: Archives of Internal Medicine, November 14, 2011