Microanalytic acoustical voice characteristics of near-total laryngectomy

Limited acoustic data are available describing vocal characteristics of individuals after near-total laryngectomy. Computer-based acoustic analyses (FO, jitter, shimmer, signal-to-noise ratio) were performed on vowel samples produced by 20 speakers who underwent near-total laryngectomy. On the basis of data obtained, the subjects who had undergone near-total laryngectomy demonstrated (1) higher than normal and more variable modal fundamental frequency values for sustained vowels; (2) increased frequency (jitter) and amplitude (shimmer) perturbation; and (3) decreased spectral noise (signal-to-noise) components. In addition, speakers who had undergone near-total laryngectomy showed an increased percentage of unvoiced sound production during their vowel productions. The large variability and general aperiodicity of the phonatory signal during vowel production suggests an ineffective laryngeal valving system with overcompensation in attempts to generate effective voice. These findings have implications for designing behavioral therapy programs to improve voice quality in speakers who receive conservation laryngectomy procedures for treatment of laryngeal carcinoma.