The influence of stoma occlusion on aspects of tracheoesophageal voice.

In this study, speech of 21 laryngectomized patients is investigated under 2 different stoma occlusion conditions, i.e. direct digital occlusion of the stoma (by thumb or finger), and digital occlusion (by finger) via a special heat and moisture exchanger with speech valve (Provox Stomafilter). For both conditions, acoustical analyses of voice quality (various pitch, amplitude, tremor and harmonicity measures) were performed on a sustained /a/, the mean maximum phonation time was calculated, and a phonetogram was made. Acoustical analysis was possible in 13 of the 21 voices (for the other voices, the pitch was too low or the voice was too aperiodic), but no statistical significant differences were found for any of the acoustical parameters studied. However, the maximum phonation time was significantly longer, and the dynamic range significantly larger, under the Stomafilter occlusion condition. The maximum phonation time showed a relevant improvement in 57% of the patients, while the dynamic range showed a relevant improvement in 35% of the patients. In total, 75% of the patients experience an improvement in one or both of these speech characteristics when using the Stomafilter occlusion. It can be concluded that optimal stoma occlusion by means of a specialized device has a positive influence on two relevant parameters of prosthetic voice production: maximum phonation time and dynamic loudness range.