By Katherine Bouton
One of the most important things a person with hearing loss can do is to develop listening strategies. Auditory training, or auditory rehabilitation, is essentially a formal program for teaching the brain to recognize speech and other sounds that may not be as clear as they are with typical hearing. It also teaches strategies for making the most of what you hear Auditory training teaches the brain to listen.
This is especially important after getting a cochlear implant. Learning to recognize the implant’s digital signals is a little like learning a new language. And as with new languages, training and practice help.
How accurately the brain processes digital signals varies from person to person. It’s not the signal itself that determines success but the way the user’s brain processes it.
Roots in the Military
Auditory training was first developed during World War II. Then as now, many active-duty military developed hearing loss. Hearing aids were not very good and the armed forces couldn’t afford to lose these men, so the military developed techniques to augment the hearing aids.
The focus was on speech-reading as well as auditory training. Conserving the ability to speak clearly was also a goal. Patients were taught how to use language knowledge and context to fill in the gaps.
After World War II, as hearing aids improved, auditory rehab disappeared from all but a few hearing centers, including the League for the Hard of Hearing in New York (now the Center for Hearing and Communication). These days, auditory training is mandated for infants and young children receiving cochlear implants; many adult implant recipients would also benefit.
Cochlear implant centers differ in their attitudes toward rehab for adults. At the cochlear implant center where I got my implant in 2009, formal rehab was offered on an as-needed basis. I was encouraged to use the at-home rehab program offered by Advanced Bionics, the manufacturer of my implant, or Neurotone’s progressive, online LACE program. Later I participated in two different formal rehab programs in person.
Rehab is a way to train your brain to distinguish the sound of someone banging the lid on a metal trash can from the bark of a dog or a human shout. They actually do sound alike to the untrained brain. The neuroscientist Kelly Tremblay, Ph.D., of the University of Washington, advocates for all varieties of rehab. There is no one-size-fits-all. Even passively listening to sound changes brain activity, including listening to recorded books.
Helpful for Older Adults
Many studies have shown that aging affects the brain in a way that distorts and disrupts the way sound is encoded in the brain. This is true even when the sound is presented in a quiet environment, and when the audiogram suggests normal hearing. It is more significant when there is background noise.
A study in the Journal of Neurophysiology discussed this issue. Researchers Samira Anderson, Ph.D. (a 2014 Emerging Research Grants recipient) and colleagues at the University of Maryland compared the brains of adults ages 61 to 73 with those ages 18 to 27. What they found was that the brain, as it ages, becomes worse at processing speech sounds when other sounds are present at the same time. Older adults scored measurably worse on speech understanding in noisy environments than younger adults.
Both groups had normal hearing as measured by an audiogram as well as speech-in-noise tests. So what accounted for the disparity in speech understanding? The answer, alas, may lie in the aging brain. Using two different kinds of brain scans, the researchers studied the midbrain area, which processes basic sound in most vertebrates, and the cortex, which has areas dedicated to speech processing in humans. In older adults, the cortex responded more slowly in processing speech regardless of whether there was secondary noise.
New Respect for Auditory Training
As the world of hearing aids changes, many hope that audiologists will take on a greater role in auditory rehabilitation. Under the current business model, an audiologist’s income is derived primarily from the sale of hearing aids; many audiologists can’t afford to provide rehab, which is not covered by most insurance.
Some hearing health professionals feel that auditory rehab can make the difference between hearing well with aided hearing or not. If you’re new to hearing aids or to a cochlear implant, auditory training will help you adjust and ultimately “hear” better. It will help with distinguishing the difficult consonants and vowels. It will train your brain to comprehend faster. And since trying to hear is fatiguing, it may give you more listening “stamina.”
Remember, it’s not your hearing—or your hearing aid or implant—that changes. It’s your brain. With auditory training, the result can be better, faster, more accurate hearing.
This article, which originally appeared in the Spring 2019 issue of Hearing Health magazine, is excerpted from Katherine Bouton’s book “Smart Hearing“ (October 2018). Former New York Times editor and former president of the New York City Chapter of the Hearing Loss Association of America (HLAA), Boutin is a member of the national Board of Trustees of HLAA, and the author of two prior books on hearing loss: “Shouting Won’t Help” and “Living Better With Hearing Loss.” For more, see katherinebouton.com.
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Our results suggest that mature cochlear supporting cells can be reprogrammed into sensory hair cells, providing a possible target for hair cell regeneration in mammals.