Phases of Treatment Hyperbaric oxygen therapy lasts about 2.5 hours per session, and consists of three phases: Compression After you are settled in the chamber, compression takes place for about five to ten minutes. Oxygen can be heard coming into the chamber and there is a slight increase in temperature, which is controlled by our staff. You may notice pressure building in your ears, similar to the feeling experienced when landing in an airplane. During this phase, and throughout the treatment, the hyperbaric staff can assist with relieving ear discomfort or pressure. Prescribed time at pressure A treatment plan devised specifically for you determines the number of hyperbaric oxygen sessions needed and the length of time per session. Normally, patients receive 100% oxygen for one to two hours per treatment. You may spend this time in a relaxing way by sleeping, listening to music or watching television. Decompression As pressure is decreased in the chamber, the temperature drops. Symptoms are minimal during this phase, although some patients experience a "popping" noise in their ears. (Title of Photo Here)   (More Information Here)