A system, and an apparatus of speaker, and a method for forming a virtual audio is provided. The first and second ends are rigidly connected to one another and are slidingly detachable from four sides of the assembly. The communications system may further include a receiving device for receiving the modulated signal from the transmitting device. The microprocessor measures the battery pack characteristics, using look up tables in a suitable program to adjust the circuit operating modes. The titration device generates output data for adjusting the air pressure supplied to the patient as a function of an index of abnormal respiratory events included in the input data.