Two studies linked speech and voice characteristics with biological ageing and cognitive problems. The findings do not establish a diagnostic test or show that voice disorders cause dementia.
An international research team has developed a “speech clock” that estimates a person’s age from speech features. In a study of 2,928 Spanish-speaking participants from five Latin American countries, an older estimated speech age was associated with Alzheimer’s disease, some forms of frontotemporal dementia, signs of faster biological ageing and poorer cognitive-test performance.
Participants completed tasks including describing a short film, retelling a story after a 20-minute delay and naming items in set categories. An algorithm estimated age from acoustic and language features, and researchers compared that estimate with chronological age. The gap was smaller among healthy participants and wider among some people with Alzheimer’s or frontotemporal dementia. Speech age was also associated with MRI findings and blood levels of p-Tau217, a protein linked to Alzheimer’s disease.
The researchers say the measure could eventually offer a low-cost, non-invasive tool that can be administered remotely. But the study did not show that the speech clock can reliably predict who will develop cognitive decline. It is not currently a diagnostic test.
A separate study by researchers at Drexel University College of Medicine, published in the Journal of Voice, followed 833,417 people aged 50 and older. Participants with a voice disorder but no hearing loss had a 58% higher likelihood of a later dementia or cognitive-impairment diagnosis; the likelihood was 104% higher among those with both a voice disorder and hearing loss. The strongest association was among people with both conditions.
The researchers suggested that reduced social interaction may partly explain the link: people who find speaking or singing difficult or painful may avoid social activities. However, a statistical association does not show that a voice disorder causes dementia or is necessarily an early sign of Alzheimer’s disease. Further research and clinical validation are needed before either approach can be used as a reliable diagnostic or predictive tool.