| The most successful method of voice and speech rehabilitation after laryngectomy is tracheoesophageal phonation with a shunt valve. Female laryngectomees and laryngectomees with a hypotone pharyngoesophageal (PE) segment however, tend to have severe problems accepting their often weak and low-pitched tracheoesophageal (TE) shunt voice. The objective of the project is development and evaluation of a sound?producing shunt valve to improve the voice of these patients. The study is based upon previous developments within the European Eureka project "artificial larynx" (EU 723), and upon numerical simulation models developed by the Department of BioMedical Engineering at the University of Groningen. The prototype alternative sound source consists of a vibrating silicone lip, incorporated in a regular Groningen shunt valve. Prototypes of this pneumatic sound source have been tested in vitro and in vivo, using perceptual voice?quality tests, intelligibility tests and registration of aerodynamic and acoustic voice parameters using a newly developed data acquisition system, confirming clear improvement of the voice in half of the patients. Low-pitched and noisy vibration of the patients= PE segment, additionally to the sound of the prosthesis, was the main problem in the non?successful patients. Based upon these experiences, new prototypes have been developed and tested in vitro. Aero-acoustic analyses and high-speed digital image sequences of lip motion patterns were obtained for diverse lip configurations. Thus, the most promising lip configuration for clinical use was established. The resulting prototype was tested in 20 laryngectomized patients; the recordings of these in vivo tests are currently being studied. |
