There is skepticism as to whether it exists as a physical sound. In 2009, the head of audiology at Addenbrooke's Hospital in Cambridge, David Baguley, said he believed people's problems with the hum were based on the physical world about one-third of the time, and stemmed from people focusing too keenly on innocuous background sounds the other two-thirds of the time. His current research focuses on using psychology and relaxation techniques to minimise distress, which can lead to a quieting or even removal of the noise.[12]
Geoff Leventhall, a noise and vibration expert, has suggested cognitive behavioral therapy may be effective in helping those affected.[13] "It's a question of whether you tense up to the noise or are relaxed about it. The CBT was shown to work, by helping people to take a different attitude to it."[14]
"It also may be a manifestation of tinnitus."