Mrs Moon said it was important to allow her husband, who has Pick's disease, the freedom to make his own decisions.

BBC: Madeleine Moon MP's tribute to husband's carers

Liver enzyme tests are sometimes normal, and even ultrasounds and CT scans don't always pick up on the disease.

CNN: The growing culprit behind liver disease

Though these changes can go unnoticed by a person with a disease, relatives and friends more often pick up on it, but a computer algorithm that detects nuances of speech and subtle changes could detect abberations with much greater frequency.

FORBES: New Software Can Diagnose Parkinson's Disease Simply By Listening To Your Voice