Consistent, unshakeable ringing in the ears is a condition that affects 10-20% of adults around the world. Some 20% of those that have it are afflicted by a severe form of tinnitus which presents with additional symptoms such as depression, cognitive dysfunction, and stress. Up until recently, the diagnosis of the condition has relied on patients providing subjective feedback. Now, researchers in Melbourne, Australia have developed an objective measure for tinnitus, using machine learning algorithms and a process called functional near-infrared spectroscopy (fNIRS.)