In vitro and in vivo comparison of the low-resistance Groningen and the Provox tracheosophageal voice prostheses.

This study has been performed to evaluate and compare two frequently used indwelling tracheoesophageal voice prostheses, the low-resistance (LR) Groningen and the Provox voice prosthesis. The airflow resistance in vitro of the Provox prosthesis has been measured and compared to our reported results of the LR Groningen prosthesis. The in vivo study involved fifteen non-myotomized laryngectomees who randomly received one of the two prostheses. Measurements were performed of the intratracheal phonatory pressure and of voice parameters. The intelligibility of speech in noise was evaluated in eight patients. Patients preferences regarding the two prostheses were assessed. Aerodynamic measurements show the Provox voice prosthesis to have a lower airflow resistance. The median intratracheal phonatory pressure for phonation of 75 dB was significantly lower (2.1 kPa) in patients using the Provox voice prosthesis. Speech rate, maximal phonation time and maximal vocal intensity showed no significant difference. The intelligibility of speech in noise produced with the Provox was significantly better than the speech produced with the LR Groningen prosthesis. Subjectively, most patients preferred the Provox prosthesis because speech required less effort. Patients with a hypotonic pharyngoesophageal segment tended to prefer the LR Groningen prosthesis.