Masking of tinnitus and mental activity.

The aim of this study was to investigate the effects of tinnitus on mental activity. In a mixed design study, the performance of 20 subjects with tinnitus and 20 healthy control subjects was compared on the digit-symbol test, completed in three auditory conditions: silence, masking and intermittent masking. Results showed marked overall differences between patients and controls on all three conditions. Lower scores on the digit-symbol test were observed during the intermittent masking condition compared with the masking condition for the patients. There was no difference between silence (e.g. tinnitus) and the masking condition, or between silence and the intermittent masking condition. The control subjects scored lower on the task when exposed to the intermittent masking compared to both silence and masking. The patients had higher depression and anxiety scores than the controls. These findings suggest that there is a link between masking sounds and how tinnitus affects cognitive capacity.