efficiency however the presence of this absorptive damping material has an adverse affect on power consumption the amplifier output must be increased in order to overcome the drag on the cone 37 it is believed that the power output of the transducer 36 during operation as a speaker should thus preferably be within a range of around 5 to 7 watts in order to maintain efficiency and effectiveness of pulse delivery although other power requirements may be specified in specific applications a patient breaths fresh air through the passages 26 around the aperture 22 while holding the mouthpiece 24 in his or her mouth the continuous acoustic waveform or sound pulses emitted by the transducer 36 are focused through the aperture 22 directly into the patient 39 s airways simultaneously the patient breathes normally through the passages 26 which open to the air external to the chamber 27 sound is substantially prevented from escaping the housing 12 when the continuous acoustic waveform or sonic pulses are being produced primarily because of the size of the passages 26 and the presence of the damping material 39 behind the transducer 36 each of the mouthpiece passages 26 has an effective diameter that is much smaller than the predominant wavelengths of the sounds being generated by the transducer 36 on the order of less than 0 5 inch for example the wavelength of a 60 hertz sound is 18 feet the wavelength of a 1000 hertz sound is 1 09 feet and 10 000 hertz is 0 1 foot the effective passage diameter for each passage is preferably on the order of 0 050 inches to 0 075 inches or 0 004 feet which is preferably at least an order of magnitude smaller than the.