[Device for examining the state of bronchial patency using the acoustic method].

An acoustic device was proposed to detect bronchial obstruction by analysing a noise process in the laryngotracheal region at the forced expiration. Clinical trials were under way, which revealed persistent diagnosis signs of bronchial patency impairments associated with changes in the duration and shape of the envelope of a recorded acoustic signal, as well as deviations of its spectral characteristic.