A comparative study of the voice with sustained phonation of the vowel /a/ was made in 3 groups of male patients: (1) 20 patients receiving total laryngectomy for epidermoid carcinoma of the larynx who had acquired good voice quality after a phonatory fistuloplasty with a Herrmann voice prosthesis; (2) 20 patients undergoing total laryngectomy for epidermoid carcinoma of the larynx who had learned esophageal speech; and (3) 20 subjects with normal voices. Statistical analysis yielded significant differences in fundamental voice frequency between the 3 groups, with the patients with phonatory prostheses revealing the closest to a normal voice. For other parameters used, such as jitter, shimmer, and harmonics/noise ratio, voice quality with a phonatory prosthesis was similar to that obtained with esophageal speech.