The embodiments of the present tracheostomy valves include a flexible diaphragm abutting a rib shaped substantially as a flat plate. Opposite the rib, the diaphragm abuts a boss and forms an uninterrupted seal therewith. As the tracheostomized patient inhales, the diaphragm bends about the rib, interrupting the seal and allowing air to flow smoothly into the valve. The features of the various embodiments contribute to a positive seal at all times except during inhalation, and low resistance to airflow through the valve during inhalation.
