The daily job duties for RT except respiratory cure and participate medical team work, the more important role play is to assist ventilator-dependent patients to rebuild their physiological functions, to optimize their mental and physical functions under their limited living abilities so as to improve their life quality. For ventilator-dependent patients; to communicate is a very difficult course to accomplish, not only for patients themselves but also for people taking care them, so the most difficult problem for taking care ventilator-dependent patients is oral communication. If it can be facilitated by vocal devices to assist ventilator-dependent patients with clear consciousness to conduct communication; then it not only becomes easier to understand patients' demand, in the mean time, also can satisfy the patients' mental condition and improve the life quality. But how to select the adequate vocal devices and set the accompanied ventilator's readings are RT's responsibilities, RTs need to progress this kind of skill so as to provide well-arranged cares to patients.