Nasal blockage belongs to the most common symptoms of nasal diseases in vocal tract area. At the same frequency there appear acoustic symptoms, existing as the change of human voice color. Vocal and articulation disorders of the ear, nose ane throat are usually observed in the form of closed rhinolalia and this observation can be performed both by patients and other listeners as well. Nasal polyps and nasal septum deviation are frequent reason of nasal blockage connected in consequence with decreased nasal ventilation. One of the main principles of the surgical treatment performed in mentioned situations is the restoration of nasal patency. The evaluation of the influence of nasal surgery on intensification of acoustic symptoms depends on verification of parameters of the human speech signal, so it was necessary to apply objective methods. That allowed to combine results of acoustic analysis with patient’s subjective feeling and rhinomanometric evaluation of nasal patency. The main purpose of this research was to objectively evaluate the influence of surgical treatment improving nasal patency on deformation of the voice of operated patients.