An assembly for modifying airflow into a nasopharyngeal airway or trachea of a patient. A valve assembly having an inlet and an outlet attaches to a traditional airflow generator. A valve seal within the assembly is operable by a solenoid and is adapted to cycle in response to a programmable controller circuit wherein upon activation of both the airflow generator and the controller circuit, pressurized air from the airflow generator continuously enters the inlet but passes out of the outlet of the assembly only when the solenoid causes the valve seal to retract and to at least partially unblock the outlet such that the pressurized air is converted into a single, repeatable burst exiting the outlet thereby modifying the traditional airflow.