WHY DOES TINNITUS EMERGE AND PERSIST? DOES EVERYONE HAVE TINNITUS TO SOME DEGREE? In answer to this question, Jack Vernon and Barbara Tabachnich Sanders, in their book `Tinnitus Questions and Answers`, refer to a highly significant study in 1953 conducted by two tinnitus researchers, M E. Heller and M. Bergman. This study involved putting 70 adult test subjects with normal hearing and no tinnitus into a soundproof room for 5 minutes. When the subjects emerged, they were each asked to describe what they had experienced in the soundless chamber. 94% described tinnitus, exactly as hearing impaired adults with Tinnitus describe their tinnitus. Vernon then posed the idea that, depending on the situation, we might all have tinnitus. I remember Jonathan Hazell, the English E.N.T. of Tinnitus Retraining Therapy`s reputation saying that he did not have tinnitus, except when carrying out tests in a soundproof booth. I have just got off the telephone from counseling a young woman in Wodonga. She described her Tinnitus as being quiet, but it had become even quieter after having a large amount of wax removed from her ear canals. When I described the Heller and Bergman experiment to her she said it now made sense. Any improvement in a person`s hearing will see a decreased awareness of the tinnitus sound’s. WHY DO WE BECOME AWARE OF TINNITUS IN NORMAL SITUATIONS? If we accept that almost everyone can become aware of tinnitus in situations where there is no external sound, what happens to increase the volume of the tinnitus so that it can be heard as we go about our normal lives? David Baguley, when he was a Head of Audiology at Cambridge Hospital explained it in these terms: “Imagine you are lying in bed at night and hear a creak on the stairs. You have an immediate response in your muscles, breathing, heart beat.... and so on. All that begins 1/12,000th of a second after the start of the creak. The first sound of tinnitus can have the same kind of effect. The more the person worries and concentrates on the sound, the greater and more persistent the tinnitus becomes.” I have often wondered whether any of the participants in the Heller and Bergman experiment began to worry about the sounds of tinnitus they heard in the soundproof booth to the point where they developed troublesome, persistent tinnitus? CENTRAL AUDITORY GAIN The auditory system has a mechanism that can increase the perceived loudness of things that we consider important or threatening. This mechanism is called central auditory gain. In many situations this works to our advantage. A mother with a newborn child has been known to sleep through a thunderstorm, but wake to the first sound of her new baby in another room. You have all probably experienced the situation where in a crowded social gathering, you hear someone mention your name elsewhere in the room. You have no idea what the other group of people are discussing, but you do hear the mention of your name. Often while driving our brains can seem to be in ‘auto pilot’, until the siren of an emergency vehicle instantly focuses our complete attention on our driving. Unfortunately, this extraordinary mechanism of central auditory gain can also work to our detriment. If we are worried or even fearful of our tinnitus, not only may we be aware of it in quiet situations, but also due to the increased perceived volume, in a noisy environment. As we stress in our seminars, worry makes tinnitus worse. Dr. Peter Tungland, an audiological physician in Britain, in a presentation at a tinnitus conference in Cambridge, explained the problem in this way. “Many patients are already in a heightened state of arousal when they become aware of tinnitus. Most people start to worry, wondering if something is wrong with their hearing, if they have sustained damage in relation to a trauma or even thinking they may have a brain tumour. This, of course, increases the arousal further, so there may be the need to check, consciously or unconsciously on the presence of the sound in order to monitor it. By checking and rechecking, the auditory pathway of the tinnitus identification passing through the brain becomes more and more used.” |
“What started as a little track through the wood (brain) increases in size due to increased use. It may develop into a road or even a roadway, in neurological terms, because of the increased demand for neurological activity involving more and more neurons. It`s like any other learning process - with practice your brain becomes better at it”. HOW DOES THE BRAIN RESPOND TO A MALFUNCTION IN THE AUDITORY SYSTEM? Tinnitus can emerge and persist by simply hearing the first sounds of tinnitus and then worrying or even becoming fearful of the sound. Baguely and Tungland describe this process extremely well. However, I suspect that many people`s tinnitus is triggered by other factors, and then the worry and fear takes over and the tinnitus becomes an entrenched problem. Four common causes are exposure to excessive noise, periods of stress and trauma in one`s life, age related hearing loss and many prescription and non-prescription drugs. Tinnitus researcher Aage Moller, Ph. D., tried to determine what could be physically wrong in the cases of severe tinnitus and severe pain. In a paper presented at the 6th International Tinnitus Seminar in CMBRIDGE, U. K., 1999, Moller outlined his belief that pain and tinnitus are both caused by changes in the central nervous system as a consequence of the plasticity (changeability) of the central nervous system. That means that the brain can alter its function either because of specific input or because of a deprivation of input. In either case, the result can be chronic pain or chronic tinnitus. Norman Doidge in his best-selling book, ‘The Brain That Changes Itself`’, mentions that there are similarities between chronic pain and tinnitus. Phantom limbs are troubling because they give rise to chronic ‘phantom pain’ in 95% of amputees, that often persists for a lifetime. How do you remove a pain in an organ that isn`t there? Doidge also mentions that the neuroplastician Edward Taub has begun collaborative experiments in the search for a cure for tinnitus that can be caused by plastic changes in the auditory cortex. So it would seem that a certain part of the brain becomes over active in its response to a malfunction in the auditory system, thus generating the sounds of tinnitus. Neuroplasticians believe the brain attempts to ‘re-wire’ itself to restore normal function, and it is this brain activity that gives rise to chronic tinnitus. WE NOW KNOW THAT TINNITUS IS NOT AN EAR PROBLEM, BUT A BRAIN PROBLEM. THE DILEMMA IN THE EARLY STAGES OF TINNITUS I often receive phone calls from people who have only had their tinnitus for a few days or weeks. It is natural for them to want to understand what these head noises mean and how they can manage them. They are usually very worried about the tinnitus, but I explain to them by trying to find out all they can about tinnitus and reading about purported cures and treatments, they are actually in danger of increasing the volume of their tinnitus and ensuring that their tinnitus will become permanent. It is not easy, but if they can go about their normal lives and ignore the tinnitus as much as possible, there is a chance that they may only be experiencing a bout of temporary tinnitus. Tinnitus is not considered permanent until you have had it for approximately 6 months - easier said than done! My advice is usually as follows: 1. Re-assure them that tinnitus is a common condition that can be successfully managed. 2. Tell them it is unlikely that they have a treatable medical condition causing their tinnitus. However, if the tinnitus persists it is important to be examined by your G.P. and an E.N.T. to rule out this possibility. 3. Explain that they will begin to ignore their tinnitus most of the time, just as people who live on busy roads eventually ‘tune-out’ to the traffic noise. 4. Tell them that as they become more relaxed about their tinnitus, the periods when they are unaware of their tinnitus will become more frequent and of longer duration. 5. Then tell them if the tinnitus persists and it is affecting their quality of life, ring back and we can begin to discuss tinnitus management strategies, or better still, try to attend one of the Tav`s Tinnitus Management Seminars. NORMALISING YOUR LIFE: IAN PATERSON Some time ago I wrote an article entitled ‘The Fifth Key’ ( if you want a copy, email me at ian@tinnitus.org.au). In it, I wrote about the importance of people with tinnitus ‘normalizing’ their life.
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