IN-VITRO COMPARISON OF THE GRONINGEN HIGH-RESISTANCE, GRONINGEN LOW-RESISTANCE AND PROVOX SPEAKING VALVES

This paper compares the physical parameters of the newer Groningen ow resistance and Provox indwelling laryngectomy prostheses with the esta blished and original Groningen device. In vitro pressure/flow profiles were determined, using specially designed apparatus, in 44 standard G roningen high resistance (GHR), 37 Groningen low resistance (GLR) and 19 Provox tracheo-oesophageal prostheses prior to insertion. GHR valve s had significantly higher forward opening pressures than both the new er valves and the GHR was significantly higher than the Provox (p<0.01 : Mann-Whitney U-test). The mean forward resistance of GHR was signifi cantly higher than that of both; the Provox valve was significantly lo wer than that of GLR (p<0.0001: Mann-Whitney U-test). This may be of r elevance with respect to patient acceptability, voice quality and effe ctive duration of valve action.