[Articulatory compensation after supracricoid partial laryngectomy with cricohyoidoepiglottopexy]

The consequences of the modification of the glottis and the shortening of the vocal tract after supracricoid partial laryngectomy (SCPL) with cricohyoidoepiglottopexy (CHEP) were investigated prospectively on ten patients. An acoustic analysis of the transfer function of the vocal tract was performed by measuring the formant frequencies of the [a] and [i] vowels. The articulation compensatory mechanisms of the vocal tract were observed with cinefluoroscopy in order to evaluate the phonation and articulation constraints.

Ten male patients were recorded before surgery and at six, 12 and 18 months after surgery. The results were compared with those of 10 male normal speakers having the same range of age. For the acoustic measures, we tracked the three first formant frequencies of the cardinal vowels [a] and [i], before and after surgery. Articulation investigation was performed with cinefluoroscopy for the vowels [a] and [i] uttered by two of the 10 patients.

For the [a] vowel, the acoustic analysis showed higher values for all three formants, related to the shortening of the vocal tract after surgery. For the [i] vowel, the lowering of the second formant frequencies after surgery was related to an articulatory compensation. Cinefluoroscopy confirmed the shortening of the vocal tract, the tongue-root retraction for voicing and the anterior position of the tip of the tongue for the [i] vowel.

The consequences of the shortening of the vocal tract after SCPL with CHEP can be evaluated, non invasively, by means of acoustic analysis. The understanding of the articulation compensatory mechanisms resulting from voicing constraints should help voice rehabilitation and improve oral communication in such patients.