Whistlers are usually purchased by the patients themselves. Some pre-operative and post-operative patients who need to use the whistle machine for a short period of time, the hospital will give the patient to rent a period of time, relatively cheap, long-term wear the whistle machine patients, you need to buy their own. The price of the whistling machine varies, the cheapest three to four thousand dollars, the price of some high two to three million dollars, generally according to the patient whistling pressure and other circumstances to buy, expensive machine is not suitable for all, perhaps very cheap machine can solve his problem. Generally automatic whistling machine use more, because the pressure can be automatically adjusted with the obstruction of the patient’s airway, such as patients today drink or tired, sleep a little deeper at night, the pressure of the whistling machine will increase a little; some may be better today, the pressure will be reduced a little, the comfort will be better. Some patients sleep on their backs with severe obstruction, but sleeping on their sides is fine, and the pressure of the whistler is reduced when they sleep on their sides, making them more comfortable. The average price of automatic whistling machine now, imported 12,000 yuan or so, domestic 7 or 8,000 yuan or so. The consumables in the use of the whistle machine, mainly filter cotton, as well as the mask and tube. Filter cotton three months to six months must be replaced, but the cost is not high, generally a few dozen to a hundred dollars; mask if you use more care, regular cleaning, maintenance, you can use one to two years, the price is generally cheap a few hundred, expensive a couple of thousand; pipe if not broken not punctured, usually not easy to break; whistling machine if normal use, life expectancy is generally about eight to ten years, some patients are very cherished, we have seen the use of 15 years. However, the rate of renewal of the whistle machine is now very high, some patients may be replaced.