RENEE MONTAGNE, host:
Well, it is true that like much else, our hearing declines as we get older. Understanding conversations in a crowd can become particularly challenging. Now, scientists are finding activities that might prevent some of that hearing loss and even reverse the damage.
Here's NPR's Patti Neighmond.
PATTI NEIGHMOND: It starts with difficulty hearing high- frequency sounds.
Dr. SANDRA GORDON-SALANT (University of Maryland): Consonants such as S, or sss, a tuh sound. Sss. Vuh. Kuh.
NEIGHMOND: Sandra Gordon-Salant is an audiologist at the University of Maryland. She says tiny hair cells and neurons that deliver sound to the brain begin to deteriorate and die off as we age.
Dr. GORDON-SALANT: So if somebody said think and you can't hear the T-H, you don't know if they said think; you don't know if they said sink, blink.
NEIGHMOND: Then our ability to detect bits of silence between sounds begins to fail, and it's hard to keep up when someone's talking fast. It's all exacerbated in noisy environments - a crowded restaurant, for example - where you can easily be distracted by all the background chatter.
Dr. GORDON-SALANT: And especially if the information is interesting, you know. So somebody says your name, or somebody says the name of somebody you know and says a piece of juicy information - your attention is going to be distracted to that background babble.
NEIGHMOND: Nina Kraus says this is one of the most common complaints of older adults. Kraus is a neurobiologist who directs the Auditory Neuroscience Lab at Northwestern University. In earlier research, she found younger people who played musical instruments had much better hearing than non-musicians - a result, she says, of highly focused attention to the subtle differences of sound.
Dr. NINA KRAUS (Northwestern University): For example, the sound quality of the same note is different depending on whether it is played with a plucked or a bowed string.
NEIGHMOND: After years of this kind of training, musicians strengthen their ability to distinguish high and low frequencies, different tones, and even bits of silence between sounds. So Kraus wondered if musical training might help prevent age-related hearing loss. She put musicians and non-musicians between the ages of 45 and 65 to the test, asking them to repeat a variety of sentences like this...
Dr. KRAUS: The young boy left home.
NEIGHMOND: Then with some moderate chatter.
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NEIGHMOND: And finally with some pretty loud background babble.
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NEIGHMOND: The musicians were 40 percent better than the non-musicians at tuning out the background noise and hearing the sentence. Kraus also found the musicians were able to remember the sentences better, which helped them follow a line of conversation.
Dr. KRAUS: In order to listen to your friend in a noisy restaurant, you need to remember what he said a few seconds ago in order to be able to make sense of what he's saying right now.
NEIGHMOND: So if you're an older musician, Kraus says don't stop playing. And if you used to play, try dusting off the violin or piano.
There's no evidence yet that starting to play an instrument in midlife will help maintain hearing, but neurobiologist Donald Caspary says animal studies have been promising. In one, researchers trained young and old rats to identify a distinct but somewhat subtle sound.
Dr. DONALD CASPARY (Neurobiologist): So you had a series of tone pips - beep, beep, beep, beep, beep, beep - and a higher one. And the rats were trained to identify the higher ones. It took the older rats longer to learn the task, but they did it for an hour a day every day, for a month.
NEIGHMOND: Eventually, all the rats improved their capacity to hear high frequencies. During the experiment, scientists were also able to measure increases in certain chemicals in the rat's brain that are crucial for hearing. Rats' ears are similar to humans but - obviously - not the same, so more study is needed to figure out whether intense musical training might be able to do for human hearing what auditory training seems to do for rats.
Patti Neighmond, NPR News.