Residual Inhibition is a very interesting phenomenon, which I have basically recognized myself, and later I have learned that it was discovered by James Spalding (or Spaulding, not sure about this) in 1903. This phenomenon was not further investigated until the early seventies of the 20th century.
One of the theories about Residual Inhibition says that tinnitus itself is actually compensation of missing frequencies (originally heard by auditory cells that died) in the auditory center of the brain. When tones very close to to the missing frequencies reach the center, brain stops compensating and tinnitus is muted or disappears for a while.
Personally, however, I think that this theory does not make any sense as by this compensation brain causes suffering to itself.
Several attempts were made to demonstrate the efficacy of Residual Inhibition. It is not yet entirely clear why this is happening, tinnitus is still relatively little explored phenomenon, but the fact is that according to research, this therapy works on average for 5 to 8 of 10 people suffering from tinnitus, for whom, after hearing the same tone externally, disappears their own internal tone for a few seconds to minutes. The ratio of success varies according to different researches, but in any case, 50 per cent or more is a decent result.
There may be long-time or even permanent effects of Residual Inhibition:
- The most extreme case of the permanent outcome of Residual Inhibition was recorded by Jack Vernon, co-founder of ATA (American Tinnitus Asociation). When a patient who suffered from tinnitus 61 years, after listening to the tone for one minute was completely free from ringing in ears for eight weeks.
- For another patient suffering from tinnitus for 20 years, it was enough to undergo Residual Inhibition 15 minutes a day to cancel tinnitus for twelve hours.
- In my case after about four weeks of listening to 4600Hz tone in the right ear, tinnitus of the same frequency had disappeared permanently. I was listening to a very moderate volume and only intermittently. For lower frequencies my tinnitus is still there, but Residual Inhibition helps me to stop perceiving them temporarily.
- There are plenty of other similar cases.
Residual Inhibition is a safe therapy and in any case there is no hearing damage or deterioration of the condition, however there are few documented cases where the tinnitus temporarily worsened. This deterioration was back to normal after a minute. In such case, it is pointless to use the Residual Inhibition.
In my opinion at the moment this is one of the most effective non-invasive therapy that will help us overcome the time until the real cure is discovered.