The prevalence of hearing loss in adults 65 to 74 years old is lower now than it was 40 years ago, according to a study published in the May 2012 issue of Ear and Hearing. The findings are consistent with the researchers’ earlier discovery that younger adults are hearing much better than their grandparents did at their age.
The new study, funded by the National Institute on Deafness and Other Communication Disorders (NIDCD), analyzed audiometric data collected from 1999 to 2006 and compared them to similar data for adults 65 to 74 years of age that were collected 40 years earlier from the period from 1959 to 1962.
Hearing impairment in adults in this age group dropped from 48% in 1959 to 1962 to 36% in 1999 to 2006. Thus, the rate of hearing impairment for adults who are currently 65 to 74 years old is 25% better than it was for adults of the same age 40 years ago.
"It’s difficult to explain why this decrease in hearing impairment occurred, since the two age groups we looked at were born in the decades circa 1890 and 1930,” said Howard Hoffman, NIDCD epidemiologist and lead author of the paper. "They became adults before the general availability of antibiotics to treat childhood ear infections or the widespread introduction of vaccines, which have since greatly reduced the incidence of common childhood diseases such as measles and mumps that may result in permanent hearing loss.”
The researchers suggest that the improvement may owe less to advances in medical treatments, and more to incremental advances made in public health, such as sanitation and safer and healthier foods, education, and transportation.
In addition, the improvement may be due to safer working conditions, fewer noisy jobs, more use of hearing protection, less smoking, better control of infectious diseases, and, more recently, improved control of diabetes and other cardiovascular risk factors.