Passy Muir Valve (PMV) "Speaking Valve" Anatomy When placed on the hub of the tracheostomy tube or in-line with the ventilator circuit, the Passy Muir Valve redirects air flow through the vocal folds, mouth and nose enabling voice and improved communication. This one-way valve permits inspiratory but not expiratory flow. - Dr. Rishi Kumar @rishikumarmd #PassyMuirValve #PMV #Speaking #Anatomy