Present work is focused in the study of the functional alterations classed as hypofunctional and hyperfunctional, with the aim to describe the dynamic of the vocal folds in each of these manners of phonation, which allows getting accurate data to its discrimination from the non-pathological voices. Preliminary results were gotten using records from 20 subjects with non-pathological voice and 20 with functional pathology (10 hypofunctional and 10 hyperfunctional). The normal and functional alteration condition was based on the results obtained from the assessment, image and voice capture after a medical and acoustic study. The inclusion of the subjects with functional disorders inside their correct group was based on criteria related to the glottal closure and the vocal quality. The results show that the rate of amplitude between open/close and the starting point of the open phase are decisive. The data allow us to offer a new classification system of the functional voice disorders in which each group (hypofunctional and hyperfunctional) includes several subclasses, giving decisive information for the voice treatment.

Index Terms. Voice disorders. Hypofunctional. Hyperfunctional, Biomechanical Analysis. Glottal Source.