Evolution has bestowed on humans a unique combination of bone, muscle and cartilage to give us exquisite control over the sounds we make, from secretive whispers to belting arias. Our voices allow us to express a vast range of thought and feeling. But they also offer clues to the inner workings of our bodies.
Researchers at the Universidad Politechnica de Madrid, Johns Hopkins University and Massachusetts Institute of Technology believe that we may be able to use the voice to diagnose Parkinson’s disease, an illness that is notoriously difficult to detect. Neither lab tests nor brain imaging can definitively identify it at present, but since the disease disrupts all of the body’s motor systems, it may often be discernible in speech. These scientists are analysing the range of sound frequencies that patients produce to see whether the changes that Parkinson’s causes in our muscles also affect how subjects talk. They have developed a technique that, they claim, can identify nearly 90% of previously diagnosed Parkinson’s sufferers, more accurate than any other single test.
The voice may also offer clues about illnesses with few physical indicators. Sonde Health, a medical firm in Boston, is working on a means to diagnose mental-health disorders from postpartum depression to anxiety. They claim to be able to detect vocal jitters, slurring, elongation of sounds and changes in vocal quality that are common among many sufferers but may not be audible to human ears. Similarly PeakProfiling, a Berlin-based company, is scrutinising variations in the loudness, articulation, tempo and rhythm of voices to help to identify adhd and Alzheimer’s. The idea of diagnosis through talking, long limited to the realm of psychotherapy, may be about to take on a new dimension.•