Aerodynamic characteristics of tracheostomy speaking valves: An updated report

Two analyses were conducted to define some aerodynamic properties of one-wa y speaking valves designed for use with the tracheotomized patient. In the first analysis, the resistance to airflow of six different valves was deter mined during steady-state flow testing at rates of .450, .500, and .550 l/s . Significant differences among the valves were established only at the low est flow rate. All valves exhibited relatively low resistance in the range of nasal resistance reported for normal adults. In the second analysis, the aerodynamic integrity of the valves was assessed during repetition of the syllable /pa/ under a condition used to simulate tracheostomy speech produc tion. Significant differences were Found among the valves in terms of air l oss occurring during the rise in pressure associated with the production of the consonant /p/. Valves with diaphragms open at atmospheric pressure con sistently exhibited air loss. Average slope of the rise in pressure for one of the valves tested was significantly greater, suggesting increased work during speech production. The results these analyses suggest that although the inspiratory resistance to airflow was similar among various one-way spe aking valves, some valves exhibit air loss during speech production.