The average American spends more than four and a half hours each day looking at their smartphone. Some people already use their devices to track their fitness levels, sleep, and weight. Scientists are now asking: Could this piece of equipment that collects and contains so much data about us help track our brain health—or even help detect the earliest signs of cognitive decline?

Some diagnostic technology for dementia involves tracking vocal changes. This is one area where smartphones could come into play. Researchers are developing apps that listen to snippets of your voice throughout the day. The apps analyze subtle changes in what you say and how you say it. These changes, called digital vocal biomarkers, could help people track people’s brain health and may also screen for signs of cognitive issues.

How does it work?

Researchers have found that changes in your brain and mental health affect how you speak. For example, when someone is stressed or anxious, the muscles in the throat can tense up, affecting the tone, pitch, or other qualities of speech. Some of these changes might also foretell cognitive impairment and other forms of dementia.

A 2023 study found that some digital biomarkers related to word use, grammar, and speech structure may correlate to the build-up of beta-amyloids—protein plaques that appear in brains with Alzheimer’s. Like physical plaque build-up, these vocal biomarkers could appear before other signs of memory loss or cognitive decline. 

From smartphones to doctor’s offices

Apps that detect vocal biomarkers aren’t available directly for anyone to download. Sonde Health recently released a cognitive fitness tracker that other companies can integrate into other smart devices and platforms. It is intended to be used like a smartwatch or Fitbit and not as a diagnostic tool.

Other researchers are testing vocal biomarkers to help diagnose Alzheimer’s sooner. Barcelona-based startup Accexible is developing screening tools for clinicians that screen for mild cognitive impairment by analyzing 30-60 seconds of speech. It is being tested in more than 10,000 patients in 17 different clinical trials across Spain, Colombia, Mexico, the UK, and the U.S. 

The researchers behind the app say that it can accurately tell whether someone has mild cognitive issues correctly nearly 9 out of 10 times.

Aural Analytics develops apps that help monitor brain health and cognition by analyzing a few snippets of speech. In 2022, the company registered the Speech Vitals computerized cognitive assessment, which can now be used to monitor changes in cognitive health over time. 

Meanwhile, Winterlight Labs developed a tablet-based speech assessment to monitor and screen for cognitive impairment and Alzheimer’s disease, measuring whether someone is responding to a new treatment. Researchers are using the app across Phase 2 and Phase 3 Alzheimer’s clinical trials, as a cognitive screening tool and to test if these changes correlate to how well or not someone responds to treatment. 

The bottom line? More research is needed to determine how well these work and how helpful they can be, but these apps and programs could make diagnosis faster, easier and more accessible in the future.