Psychological and physiological habituation are major goals in the treatment of patients suffering from chronic tinnitus. This study evaluates whether sound stimulation provided by use of low level white noise generators (NG) enhances the effects of cognitive-behavioral treatment (CBT). 124 outpatients with tinnitus of >6 months received manualized group treatment and were randomly assigned to the NG/no NG conditions. Those with moderate tinnitus-related distress obtained four sessions focusing on education, while severely distressed subjects were treated according to a full 10-session CBT program. Outcome was assessed at post-treatment and at 6- and 18-month follow-up. No additive effects due to the NGs could be demonstrated. All groups improved significantly on measures of tinnitus-related distress, dysfunctional cognitions, general psychopathology, depression, hypochondriasis and psychosocial functioning. Beneficial effects of the NGs were only observed for patients with concurrent tinnitus and hyperacusis. As systematic physical stimulation of the auditory system does not further improve the effects of CBT, the importance and strength of psychological interventions are emphasized. The clinical relevance of recently developed "retraining" approaches accentuating physical stimulation should be reconsidered.