The Passy-Muir speaking valves for the tracheostomy tube or ventilator are described at this commercial site. Advantages for speech and swallowing are discussed. The Children's Medical Center of the University of Virginia creates some of our favorite sites through their multimedia tutorials for parents and children. Their information on asthma in children includes animated diagrams and sound files of breathing. Two children briefly describe what it feels like to have asthma.
Additional sections discuss diagnostic procedures and treatment approaches.