Sorry for the delay in getting back, folks. Life and work kind of gets in the way of spending time on the board, doesn’t it? But part of my time away was spent researching your questions and composing answers offline, so it wasn’t all bonbons and Oprah. (Well, it certainly never is that, I can tell you!) Nice to see more questions too!
First, I promised Fishbicycle some comments. I came up with more than a few, actually. And, I see that some of my comments here may also address magellan01’s concerns too. Anyway, here we go…
Tinnitus is a fairly common, yet still poorly understood disorder, and this is why tinnitus questions are difficult. Research continues though, and we learn more about it every day. Fishbicycle, since you have had this for the past 11 years, if it is not greatly interfering with your life, there is likely not much you would or could do about it. But I am curious about what happened to you though, and while I won’t even attempt to guess whether there is a cause and effect between your injury and your tinnitus, I will start with the following.
Sometimes, the force of an impact can affect the fluid-filled structures of the ear. Again, this is simple physics: the bone stops moving when you hit your head, but the fluid in the inner ear keeps moving forward and puts pressure on parts of the fluid-filled chamber that were never designed to experience that sort of pressure. Examples of damage that can result in these cases would include such things as membranes being sheared or displaced. Additionally the cochlea (a fluid-filled structure housed in a bone chamber) could end up being damged from the blow, or the ossicular chain (the hammer, anvil, and stirrup bones) in the middle ear could be damaged somehow. Usually, these sorts of injuries result in some degree of hearing loss. But in your case, a hearing loss doesn’t seem to have happened. (Did it?)
Also, it is known that some medications are ototoxic (a fancy term meaning that they have side effects that adversely affect hearing), and that some medications do indeed produce tinnitus as a side effect. Could it be that some medication you were given at the time of treatment for your accident was among these?
Speaking about “ototoxic agents” reminds me of a little aside I will add. The reason why people who have too much to drink get tipsy and off-balance is because alcohol is such an ototoxic agent. It acts upon the balance mechanism of the inner ear. The drunk doesn’t fall down because he’s lost all inhibitions about how he looks and acts in others’ eyes; his balance is being temporarily physically damaged by an ototoxic agent: alcohol.
You also wanted to know about masking of tinnitus:
Phase cancellation is effective for two physical entities. Since sound is an actual waveform, two waves of equal, but opposite phase can cancel each other out.
But tinnitus is a subjective phenomena and is only heard by the person, and as such, no physical waveform is emitted from the person’s head so that it can interact (combine) with an equal but opposite waveform to cancel it out. Additionally, there are very few pure tones in real life (the only ones I have ever heard have been when using an audiometer or working in the hearing lab at university).
Mostly what is effective is something to mask the tinnitus. Usually a slightly broader band sound than the tinnitus itself is used as a masker. Diagnostically, we try to obtain a tinnitus match where we present various frequencies and various intensities to try and ‘match’ it a closely as possible to the person’s own tinnitus. This exercise is highly subjective. We can then prescribe tinnitus maskers (device that looks much like a hearing aid, and in some cases, can also be used as a hearing aid). In 17 years of practice, I can recall only one or two tinnitus maskers being judged by the patient as being effective enough to purchase. As these devices make noise, most people don’t want to listen to it–they eventually decide to listen to their tinnitus instead!
If tinnitus is causing sleep disturbances, it is possible to mask it by using a commercially available device. CDs with broad band white noise or natural masking sounds are available. Some people find relief in different sound tracks that emulate rain forest, seaside, rainy day environments, and many others. Sound pillows with small speakers embedded in the pillows are offered by several manufacturers. It may even be as simple as tuning the bedside radio to a point between two stations to get that “white” noise which can then be made louder or softer. This will usually mask the tinnitus so that you can get to sleep.
But what if the tinnitus is to the point where the quality of your life is degraded? Are there any therapies for tinnitus?
There are some. Most notably there is Tinnitus Retraining Therapy (TRT). It has been developed by Dr. P. Jastreboff and Dr. J. Hazell, and has received a great deal of attention in the past decade. It is based on a neurophysiological principle and has shown some positive results as a form of therapy in helping people recover from tinnitus. (As part of my doctoral program, I get to take a class on tinnitus with Dr. Jastreboff! Only an audiologist could get excited about it.)
Basically, TRT is a ‘re-training’ program in which the neural plasticity of the brain is used to an advantage. Our brains are able to increase or decrease the amount of attention paid to various stimuli (internal and external). This ability is subconscious, and it is governed by the limbic system of the brain. The limbic system is not only responsible for such physical things as our heart rate and hormone production, it is also responsible for our emotional feelings of well-being or distress.
When a person is experiencing tinnitus, there can be a negative subconscious reaction, which will affect the limbic system, which is closely tied to the autonomic nervous system. This will eventually lead to a conscious reaction, which is all part of a cycle of events that can bring great frustration and stress to a person’s life. It is a sort of cascade effect: tinnitus leads to a subconscious negative response which in turn leads to negative emotions.
TRT uses two basic principles: One is to use sound therapy to help with recovery. The second is to provide directive counseling by a specially trained and experienced clinician (usually an audiologist or a psychologist). The therapy can be lengthy, ranging from several months to a year or so in duration, it requires commitment from the patient, and may or may not be covered by insurance. It can be expensive.
I have no direct experience in this therapy (yet), so I cannot offer much more that what is stated above. But I hope I have addressed your questions somehow. As you can tell, it sure wasn’t bonbons and Oprah!
