Over the years, many characteristics have contributed to defining subglottic pressure (Psub).A universal concept is that without subglottic pressure, voice production would not be possible, as it is essential for sound emission.
Some authors describe it as the pressure generated below the vocal cords, while others define it as the pressure exerted by air at the tracheal level beneath the closed glottis.
In both cases, this air acts as a force, an upward energy beneath the closed true vocal cords (TVCs). By overcoming their adductory resistance, it initiates their oscillation, thereby modifying the intensity of the emitted sound and the Fundamental Frequency (F0).
What factors determine the intensity necessary to initiate phonation?
The viscosity of the TVC tissues
The degree of TVC adduction
Studies show that the minimum pressure required to produce a vocal sound is 3 cm² H2O, while the minimum pressure to sustain speech is 5-10 cm² H2O.
One of the goals of voice rehabilitation is to help the patient increase sound intensity without raising F0.
The intervention of an osteopath, aimed at eliminating peripheral somatic and systemic resistances and rebalancing systems, is a valuable tool available to voice professionals.
Valentina Carlile - Osteopath specializing in Osteopathy for Voice and Speech Disorders since 2002. For information and bookings, visit the Contact page.
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