Intensity and fundamental frequency control in tracheoesophageal voice

Nowadays tracheoesophageal (TE) voice prostheses after total laryngectomy are widely used. Data on maximum phonation time and spectrum have been studied by different authors and are well known. On the contrary intensity and fundamental frequency (Fo) control have not received much attention. Intensity and Fo have an important role in the prosodic aspects of speech. Fo variations have been studied in tone language speakers, but the ability to voluntarily change intensity and Fo have been little investigated so far. The aim of study is to analyze the ability of TE voice users to change intensity and Fo. Twelve male subjects who underwent total laryngectomy, in whom a TE prosthesis was inserted, were considered. Maximum phonation time (MPT) was calculated. Each subject was asked to utter an /a/ as loud as possible and an /a/ as soft as possible. Each subject was then asked to utter an /a/ at comfortable pitch and than at an interval of a fifth. Intensity as well as Fo variations were compared with Wilcoxon signed rank test. Correlation between MPT and variation in intensity and in Fo as well as between these two last variables was calculated through Spearman’s rank correlation coefficient. Mean MPT was 8 (± 3.8) sec. Mean energy was 50 (±4.8) dB SPL for soft phonation and 68 (±4.7) dB SPL for loud phonation. The difference observed was statistically significant (p < 0.02). Mean Fo values were 106 (±14) Hz and 135 (±34) Hz at the interval of a fifth. The difference observed was statistically significant (p < 0.02). TE voice users were able to change intensity and Fo, but their control was rather poor. Variations in intesity as well as Fo did not show any correlation with MPT, nor they correlated between each other. In conclusion TE voice allows small Fo variations, but their control appears difficult. On the contrary intensity variations appear larger and the control somewhat easier.