A comparative study was made of the voices of three groups of male patients by acoustic analysis of sustained phonation of the vowel /a/: 1) 20 patients who had undergone total laryngectomy and phonatory fistuloplasty, fitted with a Herrmann voice prosthesis, who had achieved successful prosthetic speech; 2) 20 laryngectomized patients with good quality esophageal speech, and 3) 20 subjects with normal voices. Statistical analysis of fundamental frequency disclosed significant differences between groups, the group with phonatory prostheses having the closest to normal voice of the fistuloplastic groups. There were no statistically significant differences in jitter, shimmer, and the harmonic-to-noise ratio between the esophageal and prosthetic voice groups, which suggests that the disturbances in the vibratory esophageal ring were similar.