[Dysphonia: current methods of evaluation].

Abstract

OBJECTIVES: The aim of this review article was to provide an update on current techniques for evaluation of dysphonia in routine clinical practice. MATERIALS AND METHODS: Recent medical and other scientific literature was reviewed and pertinent current theories concerning the physiology of laryngeal function described. RESULTS: Perceptual voice quality evaluation by a professional jury of listeners is still considered to be the most reliable and complete means of evaluating pathologic voice, even though it is difficult to perform in routine and the results lack reproducibility. The objective evaluation of the vocal fundamental frequency and its variations and the spectral characteristics of voice has the advantage of being simple to perform, reproducible and quantifiable. However, automatic measurements need to be analyzed with precaution for severe dysphonia, the computer algorithms being designed for voices retaining a certain periodicity. Aerodynamic measurements are quantifiable and reproducible and provide information as to the quality of laryngeal function as a transducer of aerodynamic energy into acoustic energy. Videostroboscopy and electroglottography provide information as to the quality of the laryngeal vibrations, the source of sound production. CONCLUSIONS: All of these types of analysis are complementary, informing as to different aspects of vocal quality and laryngeal function. No one measurement alone can diagnose or characterize dysphonia.