This is a 3-D image of the left brain hemisphere of a patient with tinnitus (right) and the part of that hemisphere containing primary auditory cortex (left). Black dots indicate all the sites recorded from. Colored circles indicate electrodes at which the strength of ongoing brain activity correlated with the current strength of tinnitus perceived by the patient. Different colors indicate different frequencies of brain activity (blue = low, magenta = middle, orange = high) whose strength changed alongside tinnitus. Green squares indicate sites where the interaction between these different frequencies changed alongside changes in tinnitus.