Acoustic voice analysis. On documentation of voice rehabilitation after laser surgery laryngeal carcinoma resection

Abstract

Following curative minimal-invasive laser resection of T1-T3 laryngeal carcinomas, patients were subjected to an intensive voice rehabilitation. Therapy was effected twice a day for approximately 2 months, utilizing the concept of functional voice therapy. Before and after rehabilitation, acoustic analyses were made by using two different computer-supported measuring systems: (1) the "multidimensional voice program" (Kay Elementrics Corp.) and (2) a novel software program developed in Göttingen that includes a new voice quality parameter based on correlations between frequency bands. Acoustic analyses showed superiority of the glottal versus supraglottal compensatory phonation. Findings showed that not all acoustic parameters equally documented voice improvement after rehabilitation. The standard deviation of fundamental frequency was the only parameter showing a significant post-therapeutic improvement. A further suitable acoustic method proved to be the voice quality parameter that has been newly introduced by us. In contrast to analogous parameters of other methods, this approach is independent of the exact periodicity of the glottal excitation function, thus permitting reliable results to be obtained even with aphonic or heavily dysphonic voices.