Approximately 48 million Americans experience hearing loss to some degree. Those with a hearing impairment in Los Angeles are most likely to develop the condition as a result of noise exposure or natural aging. While hearing protection can help prevent the former, there is little that can be done to stop age-related hearing loss. Scientists released a report in April that may offer some hope.
Why Age Causes a Decline in Hearing
About one in five people in Los Angeles will develop hearing loss. The condition is often related to natural aging; about 25 percent of Americans aged 65-74 has hearing loss related to natural aging. By age 75, your odds of having a hearing impairment are 50 percent. Blame this on the cumulative effects of a lifetime of noise exposure. Loud noise permanently damages tiny hair cells in the cochlea that are responsible for hearing; once destroyed, they cannot grow back. This increases the risk of a number of physical, social and psychological problems ranging from isolation and depression to diabetes and dementia. Hearing protection is the only effective way to prevent hearing loss, but sometimes even that isn’t enough. Often, genetics are the root cause of hearing loss as we age.
This makes the recent discovery of 38 new genes responsible for hearing loss a breakthrough that may result in better treatment options. Karen Steel, a neuroscientist at King’s College in London, led a research team devoted to studying the underlying causes of progressive hearing loss. The group looked at 1,200 different mice, each with a mutation in a different gene. They tested the hearing of each mouse, looking specifically at those brain cells responsible for processing sound, in order to detect even mild forms of hearing loss. Results were published in the journal PLOS Biology.
Researchers tested 1,211 genes in total and found that 38 of those – a little over three percent – were associated with hearing loss in mice. Extrapolating this data, scientists believe that out of the tens of thousands of genes that exist, there are probably 1,000 total that are involved in hearing loss. Interestingly, the tests also revealed 10 genes that can help maintain hearing with age.
“Our results tell us that there are a large number of genes involved in deafness…and many different types of abnormality of the auditory system that can lead to hearing loss,” Steel says. This means it is unlikely a “one-size-fits-all” treatment for hearing loss will ever be found; instead, the focus should be on developing better diagnostic tools to distinguish between different types of hearing problems. Identifying and classifying the genes responsible for early-onset hearing loss might someday allow doctors to take a proactive approach to treating – and maybe even preventing – hearing-loss related to aging.