Idiopathic sudden sensorineural hearing loss (ISSHL) is common and often results in permanent hearing loss. It therefore has a high impact on the well-being of those affected. Tinnitus (abnormal persistent noises or ringing in the ear) is similarly common and often accompanies the hearing loss. Although the cause of these complaints is not clear, they may be related to a lack of oxygen secondary to a vascular problem not yet identified. Hyperbaric oxygen therapy (HBOT) involves breathing pure oxygen in a specially designed chamber and it is sometimes used as a treatment to increase the supply of oxygen to the ear and brain in an attempt to reduce the severity of hearing loss and tinnitus.
We found some evidence from seven small trials of generally poor quality, that hearing may be improved in people with ISSHL and possibly that tinnitus may also be improved. This may only be true if HBOT is used within two weeks of the onset of problems and there is no evidence that HBOT can help people who have been deaf for some months. Further research is needed.