The voice is probably the most widespread musical instrument. The vocal folds are set into vibration by an overpressure of air in the lungs, the subglottal pressure being the main tool for varying vocal loudness. The sound is gerenated by the vocal fold vibrations which chop the airstream from the lungs into a pulsating airflow. This signal is filtered by the vocal tract resonator.
Breathing is obviously of relevance to voice production.
A desirable voice quality and vocal health are important goals both in singing teachers studios and in voice clinics, and according to experience, breathing strategy is highly relevant to achieve these goals. In particular, many voice disorders, especially in women, are functional, i.e., caused by inappropriate phonatory habits. Voice therapy is often an appropriate treatment where one important component is to give the patient an adequate breathing technique. Subglottal pressure is regulated by both active and passive forces. The active forces are supplied by the respiratory muscles.