June 14, 2006 -- Blacks hear better than whites and Mexican-Americans; and women hear better than men.
And -- in what may be a surprise to some - researchers say tests show little difference in average hearing scores for American adults since the early 70s.
Those findings are based on hearing tests given to 5,112 adults aged 20 to 69 from 1999 to 2004.
The nationally representative group included 1,245 Mexican-Americans, 2,518 whites who weren't Hispanic, 1,077 blacks who weren't Hispanic, and 272 people of other racial/ethnic groups who weren't Hispanic. The CDC's William Murphy, PhD, who worked on the study, provided those figures in an email to WebMD.
The tests checked for hearing threshold, or the softest sound a person can hear.
Murphy's team used the test results to estimate the overall hearing sensitivity for the U.S. They presented their findings last week at the Acoustical Society of America's 151st meeting, held in Providence, R.I.
Top Hearing Scores
The results show blacks, on average, had the best hearing threshold, followed by Mexican-Americans, with whites in third place. The reasons for those racial and ethnic gaps aren't clear from the study.
In addition, average hearing thresholds were generally better for women than for men.
The tests also show that, as expected, hearing tends to decline with age.
The nation's last hearing check was 35 years ago. Average hearing scores for adult Americans were similar back then, note Murphy and colleagues.
They note that "hearing loss can be caused by a myriad of factors" including age, noise exposure on the job or during leisure time, health problems, and physical trauma. Some people may be genetically more likely to develop hearing problems than others, the researchers also note.
Some of those factors -- including age and genetics -- can't be changed. But noise exposure can often be reduced by simple steps, such as turning down the volume on a headset or wearing protective devices in noisy areas, such as construction sites.
"Effective prevention programs could therefore make a large impact in reducing the prevalence of hearing loss in the United States," Murphy's team writes.