Researchers have developed a computer-based system capable of estimating a person’s biological age by analyzing characteristics of their speech, according to a new study. The tool, described as a "speech clock," examines multiple vocal features—including speaking speed, pause duration, pitch, and vocabulary choice—to gauge how well the brain and body are aging.

The system was tested on nearly 3,000 Spanish-speaking adults from Argentina, Chile, Colombia, Mexico, and Peru. Participants included both healthy individuals and patients diagnosed with mild cognitive impairment, Alzheimer’s disease, and various types of frontotemporal dementia. The model generated a "speech age gap," which represents the difference between a person’s actual chronological age and the age suggested by their voice.

Results showed that individuals whose speech appeared older than their true age tended to exhibit signs of accelerated brain and biological aging. These participants performed worse on standard tests measuring memory, cognitive function, and planning abilities. In those diagnosed with Alzheimer’s disease, a larger speech age gap also correlated with elevated blood levels of p-tau217, a protein recognized as an important biomarker of the condition.

The study found that younger-sounding speech was generally characterized by faster and more fluent delivery with shorter pauses. These participants also used more precise vocabulary, substituting terms like "spaniel" rather than the more general "dog."

Agustin Ibañez, professor of brain health at Trinity College Dublin and the study’s senior author, emphasized that voices may contain much more information about the ageing process than previously understood. He noted the potential for speech analysis to serve as a rapid, low-cost screening method for early detection of neurodegenerative diseases such as dementia.

The findings, published in the journal Science Advances, suggest that if validated through longitudinal studies and broader populations, voice analysis could become a scalable tool for monitoring both healthy and accelerated ageing. This approach may transform everyday speech into a novel means of gaining insight into biological ageing processes.