Karen Helfer, associate professor of Communication Disorders, has received a five year, $1.3 million grant from the NIH’s National Institute for Deafness and Other Communication Disorders to conduct a series of studies to determine what is going on in difficult listening situations where hearing aids often don’t help, and explore ways to assist millions of older Americans to do better.
Though most people with hearing loss are treated with hearing aids, the devices are not very helpful in situations where many people are talking at once or there is background noise, says Helfer, an expert in aging and speech communication. Though these problems are most apparent in people who have hearing loss, even older adults with normal hearing sensitivity often report challenges in adverse listening environments.
This leaves many older people feeling isolated in social situations such as restaurants and dinner parties, and leads to difficulty with many other activities such as understanding travel announcements in busy airports. More than 13 million Americans over 65 have hearing loss, she notes, and the number is expected to go over 27 million by 2030.
The adoption rate for hearing aids is very low, Helfer says. Only about 25 percent of people who could use them actually choose to, in part because hearing aids are not that effective in difficult-listening situations where there is a lot of background noise or other people talking. “They’re most effective in quiet situations.”
“This is definitely a quality-of-life issue. There are really strong links between hearing loss and social isolation and a lot of other negative consequences. Think about grandparents sharing a family dinner. A bunch of people they love are around the table and everyone’s chatting, dishes are clinking, the kids are giggling. If you can’t hear effectively you can’t participate. If you can’t participate you withdraw, which is painful emotionally. And in a situation like that, hearing aids are not very helpful.”
Over the coming five years Helfer and her colleagues hope to enroll more than 250 older and middle-aged subjects in hearing studies, about half between 45 and 64 years and half over 65. Overall the goal is to improve the way professionals help people, even those with little or no hearing loss, who have trouble in difficult listening situations as they get older.
Participants in the studies will be asked to make two visits to a hearing laboratory on campus for tests of basic hearing, cognition, working memory, processing speed and ability to ignore selected information, also known as inhibition.
Helfer says restoring audibility is not enough to ensure successful communication in situations where listeners must ignore the distracting speech of other talkers. One goal of her research is to see if there are non-hearing-related behavior strategies older adults can learn to help them focus on a single speaker in adverse listening environments. Her immediate goal is to understand why competing speech signals are so disruptive to older people and how age-related changes in cognitive abilities may contribute to their reduced ability to cope.
Past research has yielded conflicting conclusions about the relative importance of age-related sensory factors and age-related cognitive changes in explaining speech-understanding difficulties, the researcher says. By examining how individual differences in working memory, processing speed, inhibitory control and hearing loss interact with stimulus-related factors, she and colleagues hope to understand the situation better.
“People may have difficulties not related to hearing, and we want to get at those,” she adds. “I think someday there will be more cognitive-based approaches we can take to help people in difficult-listening situations. For example, if our research suggests that working memory is related to problems understanding speech in difficult listening situations, the next step would be to see if working memory training techniques, which are already available, can help people cope in these environments.”