A study of 56 patients was undertaken to determine whether there is a difference in the effect of the laryngeal mask airway and the endotracheal tube on the vocal tract after short-duration anaesthesia. All the patients were interviewed pre- and post-operatively.In 43 patients, it was possible to assess the larynx using videoendoscopy and videostrobolaryngoscopy both pre- and post-operatively. Selected acoustic characteristics were investigated in 51 patients pre- and 18–24 h post-operatively. Thirty-four patients that did not have anaesthesia were used as an age-matched control.

The interview showed, that patients in the LMA group complained less frequently of having post-operative complained less frequently of having post-operative demonstrated minor lesions of the vocal tract in six patients in the ETT group and in one patient in the LMA group. Of the 12 voice variables evaluated, there was no significant difference in any parameter between the two groups. Both groups had a higher fundamental frequency post-operatively.