[Increase in the abdominal respiratory movements during the sudden passage from a conversational voice to a loud voice].
The passage of the simple conversational voice to a loud voice is accompanied by an increase in the muscular tensions as well as increase in the mobilized volumes of air.


OBJECTIVE
We sought to know if these additional volumes were mobilized rather by a thoracic breathing or an abdominal breathing and if this effort were accompanied by a reduction in the variability of the movements.


METHODS
The study presented is a prospective experimental study undertaken on healthy subjects (10 subjects) of which we analyzed the spontaneous vocal behavior (conversation with the experimenter) in the medium of vocal spots lures (production of vowels) in a calm environment allowing a conversational voice (condition 1) and in a noisy environment obliging the subjects abruptly to use a strong voice (condition 2). Thoracic and abdominal volumes were recorded using belts provided with pressure pick-ups, while the voice was synchronized with the recordings.


RESULTS
The results show a reduction in the number of rheses realized with abdominal volumes and a reduction in the abdominal volumes mobilized in condition 2, testifying to a preferential use of thoracic breathing in loud voice. They also show a reduction in the number of movements of the inspiratory type (increase in the thoracic diameter or reduction in the abdominal diameter) during the phonatory phase in condition 2, which testifies to a reduction in the variability of the strategies used by the subjects.


CONCLUSIONS
The sudden passage to a loud voice because of the appearance of an ambient noise leads to an increase of the use of thoracic breathing, which is in agreement with the concept of voice of distress or of emergency suggested by Le Huche.
Cayreyre
Fl
F
Laboratoire d'Audio-Phonologie Expérimentale et Clinique de l'Université de la Méditerranée, CHU Timone, Fédération ORL, Marseille, France.
Akl
L
L
Amy de la Bretèque
B
B
Ouaknine
M
M
Giovanni
A
A