Understanding the challenges of older adults in perceiving young children’s speech: The role of vowel space characteristics

As people age, they increasingly report difficulties understanding adults’ speech, suggesting even greater challenges with young children, whose speech often has lower intelligibility. Few studies, however, have explored older adults’ perception of young children’s speech or the reasons behind these difficulties. We hypothesized that the frequency region and area of the vowel space influence older adults’ ability to understand young children’s speech. Our pilot study showed that older adults’ average perception accuracy for six children was below 50%. Analysis revealed that the frequency region of the vowel space, rather than its area, had a greater impact on older adults’ speech perception. This differs from young adults, for whom vowel space area is more significant. Additionally, children whose vowel space was closer to adults’ vowel space were more intelligible to older adults (r = 0.89). In this study, expert listeners, specifically speech-language pathologists, will rate children’s intelligibility and categorize them into low and high intelligibility groups. We will test whether expert ratings correlate with the area and frequency region of children’s vowel spaces. Results from hypothesis testing will be reported to better understand the relationship between vowel space characteristics and intelligibility when testing perception in older adults.