Study suggests how ‘speech age gap’ may provide signs of cognitive and brain health decline
How you speak may in the future offer clinicians a way to predict diseases like dementia, a new study suggests.
The project – involving researchers from Trinity College Dublin’s Global Brain Health Institute – shows how a ‘speech clock’ that can estimate a person’s chronological age from hundreds of acoustic and linguistic characteristics of their speech.
The difference between a person’s actual age and their speech-predicted age (known as speech age gaps) was also linked to several markers including brain and biological aging, cognition and dementia.
The study involved almost 3,000 participants from South America. Healthy participants showed the lowest speech age gaps, while progressively larger gaps were observed across Alzheimer’s disease and forms of frontotemporal dementia.
“Our voice appears to contain much more information about aging than we previously recognised,” said Agustin Ibanez, TCD professor in brain health and senior author of the study.
“It captures both the passage of chronological time and signals coming from cognition, the brain, systemic biology, and even our accumulated social environment. This raises the possibility that something as simple and accessible as speech clocks, maybe combined with biomarkers, could eventually complement much more expensive measures of aging.”
Using machine learning, the researchers analysed hundreds of features capturing how people speak – such as speed, pauses, pitch, emotional content, vocabulary, semantic precision, and the amount and organisation of verbal output – and combined these features to estimate chronological age.
People whose speech appears older than expected for their chronological age also showed signs of accelerated aging across several biological and clinical systems. The speech age gap was associated with brain age measured using structural and functional neuroimaging. It was also related to epigenetic aging, measured through three independent DNA-methylation clocks, that estimate how biologically ‘old’ the body appears based on age-related chemical changes in DNA.
Greater speech-age acceleration was also associated with poorer global cognition, executive function, functional abilities, and memory.
While promising the study’s authors note that the research findings are primarily cross-sectional, meaning that it cannot establish whether an older-appearing speech profile predicts who will subsequently develop cognitive decline or dementia.
Longitudinal studies, validation in additional languages and cultures, and testing in more naturalistic speech settings will be required before ‘speech clocks’ can be used as a diagnostic tool for dementia.
“The broader finding is nevertheless striking in that a person’s voice may provide a remarkably compact readout of multiple dimensions of aging,” added Prof. Ibanez.
“From chronological age to brain aging, epigenetic aging, cognition, Alzheimer’s-related pathology, social exposures, and dementia phenotypes, information traditionally obtained through very different and often expensive measurements appears to converge, at least partly, in the way we speak.
“If confirmed longitudinally and across populations, speech could ultimately become one of the most scalable tools for monitoring healthy and accelerated aging—potentially transforming an everyday human behaviour into a window onto the biology of aging.”
Read the study: Speech clocks decode dementia phenotypes, social exposome, and biological aging – Science Advances.