Perceptual evaluation of vocal behaviour

Speech therapists define their voice therapy by perceptual evaluation of vocal behaviour and speaking technique. In the diagnostic phase they identify vocal problems and they spot the imperfections which may be present. In their therapy they plan a course of action to remove them. While modifying vocal behaviour, they all treat aspects like hypo- and hyperfunction, breath control and support, voice onset, resonance and adjustment of vocal tract. On the surface it seems they all agree in clinical diagnosis, but there have been no studies of consensus or agreement. This study analyses the parameters and the (inter-rater and intra-rater) reliability of perceptual evaluations of videotaped subjects by speech therapists. There is not only confusion about nomenclature which makes it difficult to compare the evaluation, but statistical analysis shows poor and less than moderate interobserver and intraobserver agreement in the assessment of voicing.