[Comparative study of respiratory mechanisms between professional lyrical singers and beginners]

The apprenticeship for classical singing requires years of training due to its complexity. This training is directed at the different levels of the vocal apparatus: the source of energy or air flow (lungs), the vibrator (vocal cords) and the resonators (bucco-pharyngeal cavity). For this study we have concentrated on the first level, that is, respiration. When a greater demand of vocal activity is required respiration becomes more sustained and more complex; this is when difficulties may be observed. Singers overcome these difficulties through different strategies according to their level of vocal training. Our study compared respiratory strategies used by professional singers and singing students (first year conservatoire students) during singing tasks; none of the subjects had any history of vocal pathology. Electromyographic analysis of muscle activity was registered for the rectus abdominals muscle, external oblique muscle and transverse muscle with surface electrodes. Kinetic analysis was used to measure thoracic cage displacement: pressure sensitive belts were placed around the pubis, the epigastric region and thorax. The subjects were asked to perform two vocal tasks: vocalization of a sustained "i" and singing of an extract of a vaccaï. Results were compared between the 7 professional singers and the 6 singing students. They allowed us to confirm the existence of distinct respiratory strategies according to the level of vocal training, as described in literature. Professional singers inhibited the activity of their rectus abdominals muscles during singing and used mostly their external oblique and transverse muscles, thus, sustaining an expanded ribcage and a longer expiratory breath. Singing students, on the other hand, worked intensively all the abdominal muscles leading to a collapse of the ribcage. Management of air was more difficult and breath was shorter. Future studies will consider a larger population sample in order to define quantitative parameters that might allow a significant differentiation of respiratory strategies between professional singers and singing students.