The Voice Handicap Index (VHI) is a widespread instrument for measuring the psycho-social handicapping effect of a voice disorder over 3 domains, the Physical (P), the Emotional (E) and the Functional (F) domain. It is a disease specific quality of life instrument and consists of 30 items/statements (10 in each domain), which are to be scored from 0 to 4 with a maximum score of 120. The higher the score, the more there is a handicapping effect caused by the voice disorder. An abridged version (10 out of the 30 statements: VHI10) has been proposed and validated. Spasmodic Dysphonia (SD) patients (adductor type) are known to report in average extremely high VHI-scores. A detailed analysis is necessary to get better understanding of this phenomenon, particularly in the scope of therapy effects with Botulinum Toxin injections.