With a growing aging population that is living longer and longer, there is increasing prominence given to the idea of healthy aging. The National Institute on Aging identifies four elements that can contribute to a productive and meaningful older life: maintaining a healthy weight, watching your diet, being physically active, and participating in hobbies and social activities. Doing these things has been linked to a lower risk of dementia and a longer life span.
Conspicuously absent on the NIH list is the role of the sound mind in healthy aging. Yet the quality of life of an older adult is tightly linked to sound and hearing. Even with all other risk factors— age, sex, education, etc.—carefully controlled for, the existence of hearing loss is strongly and independently associated with cognitive impairment. And among those with a dementia diagnosis, the rate of cognitive decline is accelerated in hearing-impaired individuals. Both the NIH and the UK’s counterpart have identified hearing loss as one of the most modifiable risk factors of dementia. The dementia-hearing link is present in the hearing brain as much as it is in the ears. Listening-in-noise ability—which requires not only hearing the signal but the ability to think about it—is reduced in older adults with Alzheimer’s disease and other forms of memory impairment.
There is another pernicious angle to the hearing-dementia link. Hearing problems, whether in the form of decreased audibility overall or difficulty hearing in noise in particular—is isolating. If you cannot hear speech well, you are less likely to go on outings with friends, attend church, call your children, or chat with the cashier at the grocery store. You tend to withdraw more and more, feel increasingly socially disconnected and lonely, and ultimately lead a less enriching life. These social factors—which do make the NIH list—are linked to dementia.
Just as a young adult can start exercising and eating well today to set herself up for healthy aging, there are things we can do for our sound minds that can pay dividends later on. Healthy aging begins in childhood, but one can also reap benefits from starting good, new practices later in life as well.
Musical training can contribute to a healthy older life. Listening to speech in noise is better in older musicians than in their non-musician peers, and we can see this reflected in the brain’s response to sound. Moreover, older adults with musical experience maintain better memory and cognitive skills than non-musicians.
My lab, Brainvolts, looked at auditory-brain function in older musicians. We recruited musicians and non-musicians between the ages of forty-five and sixty-five. The musicians had decades of continuous musical practice, beginning in childhood. After carefully screening for normal hearing and IQ, and matching the groups on cognitive ability, physical, and social activity, we tested their hearing-in-noise ability. The musicians were better at listening in noise. Then we looked at what effect making music had on the aging brain signature we had discovered previously. Remarkably, the declines in processing of all sound ingredients—timing, consistency, the works—were reduced or even nonexistent in older-adult musicians. Their brains’ responses closely resembled those of healthy young adults. Even older adults who do have ear-based hearing loss benefit from music making—listening-in-noise ability in older adult musicians with hearing loss can match or exceed that of non-musicians who have normal hearing thresholds, even those half their age.
Many of us had some musical training in the past. Just like investing a modest sum of money at a young age can pay off handsomely at retirement age, we wondered whether playing some music earlier in life could pay off even decades later. We saw that older adults with as few as three years’ experience playing an instrument many decades before exhibited signs of a “younger” brain. The benefit, though, was more modest than in the older people who had kept up their music making. It was the lifelong musicians who showed enhancements in all of the sound processing ingredients shown in figure 12.2. Other investigations of early musical training found that older adults with at least ten years of musical training had better memory, executive function, and cognitive flexibility than an otherwise well-matched group with few or no years of music.
What if you are older and you have never taken part in any music making? Will beginning musical activity now help? Yes! An older person who begins to make music today can see benefits in both neural processing and real-life listening abilities. Ten weeks of two-hour weekly group choir sessions along with weekly vocal-training sessions was associated with an improvement in listening in noise and boosted neural responses to the fundamental frequency in speech (a voice pitch cue) in adults ranging in age from the mid-fifties to late seventies. Learning piano later in life led to better listening in noise and a strengthening of the brain’s speech-motor system. Another study pitting music listening against music playing found that the sixty-to-eighty-year-olds who actually made music improved their working memory and hand coordination.
Sources of cognitive health include cognitive exercise, education level, diet, physical activity, and an active social life. Bilingualism is another factor to add to the list. Bilinguals typically outperform monolinguals on tasks that require cognitive skills like attention and inhibitory control. This edge is maintained in older bilinguals. In people with Alzheimer’s disease, the bilingual brain is able to tolerate a greater extent of brain degeneration before performance suffers. Some studies have attempted to pin a number on this finding and have claimed that speaking a second language can delay the onset of dementia four to five years.
I have attended conferences on aging where the prevailing message is OLD=BAD. This conclusion comes from looking at factors we can measure: hearing thresholds, reaction time, atrophy in the brain. What’s missing is research on the immeasurable: wisdom, patience, compassion, joy. With age we learn how to listen and what is worth listening to. The product of life experience is impossible to measure, but if it were measurable, I think there would be more conferences with the theme OLD=AWESOME.
I hope the link between hearing, thinking, and how we feel will become increasingly recognized. Time travel is still out of reach, limiting what could have been done years ago to build up our sound mind. But learning (or relearning) to play music, studying another language, and training that strengthens sound-to-meaning connections offer possibilities. Our sound minds are a conduit to living a richly interconnected life.
Excerpted from Of Sound Mind: How Our Brain Constructs a Meaningful Sonic World by Nina Kraus. Reprinted with permission from The MIT PRESS. Copyright 2021.