Can You Hear Me Now?

Improving hearing, especially in a loud environment, is just like any other skill — it takes practice.

The din of a loud restaurant or party can make conversation difficult for anyone— but for the elderly, these settings can make it nearly impossible. The mechanics of hearing decline with age, but the latest research focuses on another part of the problem — the slower processing speed of aging brains, which have to work harder to translate sound into intelligible language.

Research shows that musicians— despite often working in conditions that can produce hearing loss— are better able to pick out speech from surrounding noise as they age compared to non-musicians.  And a new study of  auditory training with a commercially available brain training program suggests that most people who are hard of hearing can develop the same skills.

In a report published in the Proceedings of the National Academy of Sciences, scientists showed that people trained for 40 hours over 8 weeks with Posit Science’s “Brain Fitness” were able to pick out 41% more words from background noise compared to those who watched educational DVD’s and were quizzed on their contents after the same amount of time. The authors, led by Nina Kraus of Northwestern University, received no funding from the makers of the program; the study was funded by the university and the National Institutes of Health.

The research included 67 older adults between 55 and 70, with an average age of 63.  The auditory training came in the form of computerized hearing tasks that primed the participants to hear better by requiring them to identify various speech sounds and distinguish between similar sounding syllables, for example, as well as repeating back words and remembering stories.

Both those who received the training and those who watched the DVDs were tested on short term memory, brain processing speed and the ability to hear speech in noisy settings. All of the participants showed improvement in these three measures, but for the first time, the scientists also documented that the sharper hearing was accompanied by earlier signaling in the brainstem. EEG electrodes on the head picked up this activity, which was related to how quickly the brain was distinguishing between sounds, such as language vs. background chatter.

As the authors write in their paper, this could represent nothing less than a “partial reversal of age-related declines” in the timing of brain signals.  In other words, the training not only improved the ability to decipher speech in noisy situations, it also sped up the brain’s ability to respond to it — bringing it to more ‘youthful’ levels.

“These results complement previous work in which we have shown that lifelong musical experience offsets age related neural timing delays,” the authors note, adding that “a partial reversal of these delays is possible with just 8 [weeks] of training.”

That doesn’t mean that “Brain Fitness” is the Fountain of Youth for being hard of hearing, however. A recent review of memory training programs for both children and adults found that these strategies don’t translate into overall improvement — meaning that you can improve recall on a specific task, but you don’t improve your memory in general. That might also be true with auditory training, but if it improves your ability to have a conversation in a noisy setting, it’s likely to be helpful in any environment where your brain has to work harder — and faster — to hear better.