The Double Whammy: Hearing and Memory Declines Lead to Speech Comprehension Difficulties in Older Adults
Three old guys are out walking. First one says, “It’s windy today!” Second one says, “No, it’s Thursday!” Third one says, “So am I! Let’s have a beer!”
Understanding speech, though seemingly automatic to the listener, is a complex ability supported by both auditory and cognitive abilities. As these latter abilities decline with age, speech comprehension also suffers. In the present study, we investigated the relative contributions of hearing loss and memory decline to speech comprehension difficulties in older adults.
This study is a longitudinal follow-up of a study conducted approximately four years ago in our lab in which a subsample of older adults (over 65 years) was retested on speech comprehension, hearing, and working memory (a type of short-term memory). We found that participants on average experienced moderate hearing loss and declined significantly on most working memory tasks.
How did these declines affect speech comprehension? The oldest participants (over 80 years) declined the most on speech comprehension, except for a group of exceptional older adults. When we examined what contributed, we found that hearing loss contributed to 34% of these speech comprehension declines, while working memory contributed an additional 66%.
Therefore, older adults’ dissatisfaction with hearing aids, which only improve hearing, is potentially due to their poorer memories. Clinicians can use these results to prepare older adults with more appropriate expectations for their hearing aids. Researchers in the emerging field of cognitive training can use these results to determine targets for training to improve speech comprehension.