Validation of a Questionnaire for Self-Evaluation of Voice at Work for Professional Voice Users
Professional voice users need their voice as a primary tool to make their living. Therefore, the adverse effects of voice disorders are especially severe for them. In spite of this so far there are no proper diagnostic instruments that address the special needs of professional voice users. The purpose of this study was to develop and validate an instrument for self-evaluation of the impact of voice problems in professional voice users. Most of the items of the questionnaire which is to function as this instrument were derived directly from the categories of 13 interviews with professional voice users (including kindergarten teachers, teachers, pastors and politicians) including questions about vocal loading and loading symptoms in their work.
The theoretical basis of the questionnaire is the structure of the International Classification of Functioning, Disability and Health (
ICF). The developed instrument was administered to 750 professional voice users all over Germany (kindergarten teachers, teachers, call-centre agents, pastors). For construct validity correlation with the Voice Handicap Index (VHI) was conducted. The internal consistency of the questionnaire proved to be good with a Cronbach's α of 0.95. Principal components analysis largely revealed the
ICF analogue built subscales. Correlation of the developed questionnaire's score and VHI score was high (r=0.85, p=0.01) and the anticipated item correlations were mostly found.
The final version of the questionnaire consists of 31 items in 5 subscales: Functions, activity, participation, environmental factors and personal factors. The Voice Profile for Professional Voice Users (VPPV) is a reliable and valid instrument that allows a comprehensive view on the complexity of the voice of professional voice users.
