Different medical and surgical methods have been tried in attempting to reduce endolymphatic pressure in M'eni`eretextquoterights disease. Pressure treatment has a role on the treatment staircase, after pharmacological treatment and before destructive methods. Pressure chamber treatment has shown that some patients respond well to the treatment with diminishing inner ear symptoms and also some hearing improvement. Earlier studies have shown that electrocochlear measurements improve after local pressure treatment in the ear. The present study was a prospective randomized placebo controlled, multicentre clinical trial. 56 patients with active M'eni`eretextquoterights disease, age 20-65 years, with a hearing loss of 20-65 dB PTA participated. A total of 31 patients completed 2 weeks use with an active apparatus (Meniett) and 25 patients completed the 2 weeks with the placebo gadget. Both machines were produced by Pascal Medical, Halmstad, Sweden. Two weeks before the start of treatment a grommet was placed in the tympanic membrane. A significant improvement concerning frequency and intensity of vertigo, dizziness, aural pressure and tinnitus was reported by the active group on the visual analogue scales (VAS) questionnaire. In the placebo group no change was the most common finding, followed by worsening of the symptoms and a few improvements. The function in professional and family life improved during active treatment and did not during placebo treatment. Pure-tone audiometry did not improve after placebo treatment, but improved at the frequencies 500 Hz and 1,000 Hz after active treatment. The study showed an improvement in the inner ear symptoms after Meniett treatment. The mechanism may be explained by the influence on the round window membrane pressure receptors or an endolymphatic flow out through the pressure release points, such as the endolymphatic duct and sac, thus activating the longitudinal flow. Other mechanisms are also possible.