Learning to control tinnitus

Tinnitus, the perception of sound in the absence of an external source, has been noted for millennia in historical medical and other texts. It affects between 10% and 15% of adults in the general population. Tinnitus can be considered to be both the perceived sound itself and the psychological reaction to it. Variability in both these factors drives the heterogeneity seen in the patient population. Here, we consider what occurs after the onset of chronic, continuous tinnitus, which lacks a cure, focusing primarily on the psychological impact on the individual. The great majority of those with chronic tinnitus learn to habituate to it, possibly exerting greater cognitive control of their emotional processing, whereas a minority report bothersome symptoms associated with their tinnitus. These symptoms include difficulties with sleeping, challenges with communication and concentration, and associated anxiety and depression. Although there have been several influential models of tinnitus generation, few have considered the process of habituation and the attendant neuroplasticity of long-term chronic tinnitus. As data accumulate from cross-sectional behavioral and brain imaging studies, the neural bases of successful habituation are becoming clearer, pointing to interconnected neural networks mediating cognition and emotion and, only secondarily, audition. What remains unclear are the longitudinal changes in these networks culminating in successful habituation, with or without an intervention. Greater knowledge of these changes will allow us to unravel the mystery of not only tinnitus but also how sound itself is consciously perceived.