I am a tinnitus sufferer. My tinnitus consists of a high frequency whistle in both ears. I have developed the Detinnitiser to treat this kind of tinnitus. The following material is my personal view on the subject, and these ideas were originally all tested on just one subject - me. Subsequently, I found my tinnitus was pretty standard, and others began to report similarly encouraging results.

THE THEORY BEHIND 'DETINNITISING'.

Tinnitus is a complex phenomenon which nobody fully understands and it is still unclear how its varieties should be classified. The type of tinnitus I can research and on which my products are based - is of course my own. In general, I've noticed my type of tinnitus is determined by the level of arousal of the nervous system and also by the other tasks being processed by the brain...

This sort of tinnitus is often associated with a corresponding 'dead spot' in the hearing system's response to sounds of similar frequencies to the tinnitus. Thus the tinnitus could be a sort of 'error signal' whereby the system compensates the lack of incoming information-bearing sound data with 'noise' of similar pitch. If we can overcome this deficiency with an additional sound stimulus, preferably incorporating additional information-bearing content, we could then make it unnecessary for the hearing system to produce the tinnitus signal. If we can replace the missing content - we can remove the tinnitus. It's as simple as that!

This is the basis of the effect known as 'residual inhibition' and the Detinnitising method is based on this. If we feed in short sound pulses similar in pitch to the tinnitus itself, these can reduce the tinnitus for a short time. Moreover, when the sound contains information-bearing content - ie. sounds incoming from the outside world - the brain will favour this over the tinnitus even more. The tinnitus can even be completely removed. However the therapeutic sounds do have to be of the right type, or the tinnitus can be made worse.

So what's going on? Maybe it could be explained like this:

TINNITUS IS ... a "noise in the ears".



• Tinnitus is a complex nervous disorder made worse by damage or decay in the hearing system, due to ageing, disease, trauma, or exposure to excessively loud sounds. Even when the cause of the tinnitus is simply damage to the hair cells in the cochlea, this can disturb the signal processing balance within the hearing system as a whole.
  
  
• The problem then becomes as much about the awareness of tinnitus as it is the source of the tinnitus. The 'noise' isn't separate; it's a general condition in the hearing system, which stretches from ear to brain. Other factors not directly related to 'hearing' can then affect it.
  
  
• Certain things can worsen it, such as lying down, time of day, napping, stress, heavy concentration, an empty stomach, unnatural jaw positions, certain foods.
  
  
• Tinnitus may be therefore linked to blood circulation, possibly in the brainstem.
  
  
• Tinnitus can also occur when the hearing system compensates for a reduction in sensory input at the same audio frequencies.
  
  
  RESIDUAL INHIBITION … how short sharp sounds can reduce tinnitus.
  
  
• The hearing system has limited processing capacity and will prioritise its tasks in order to best allocate its resources.
  
  
• When the hearing system is determining how to allocate its resources, 'dynamic' (ie. changing) incoming stimuli containing useful information will be favoured over 'static' stimuli containing no information (such as tinnitus). So it becomes much harder to hear the tinnitus when competing sounds, which are 'more interesting', are arriving in the hearing system at the same time.
  
  
• Resources cannot be re-allocated instantaneously. So, once the dynamic stimulus ceases, it takes the hearing system a short while to reset. During this time, the (static) tinnitus noise stimulus may still not be heard. Repeating a suitable short dynamic stimulus at regular intervals ensures the tinnitus remains inaudible in the gaps.
  
  
• This is the effect known as residual inhibition, whereby a pulse of sound of similar pitch to the tinnitus can suppress the tinnitus for a short time.
  
  
  PROCESS LEVEL ENGAGEMENT …keeping all the processing levels tied up at once can remove the tinnitus entirely.
  
  
• When a dynamic stimulus also contains information-bearing content (such as everyday sounds from the outside world), which are limited to the same frequency range as that occupied by the tinnitus, the hearing system will devote still deeper processing resources to this signal and will favour it over the tinnitus even more.
  
  According to this model, the hearing system processes (ie. perceives and examines) incoming stimuli at successively deeper levels in order to extract the full significance of the information contained. When all these processing levels are kept occupied, they will not have the capacity to simultaneously process a 'noise' signal such as tinnitus, which then becomes redundant.
  
  
  FREQUENCY RANGE COMPENSATION … how some types of sound can make tinnitus worse.
  
  
• In general the hearing system automatically adjusts itself to remain receptive to a balance of frequencies over the entire range.
  
  
• If this balance is already disturbed by an existing dead spot or deficiency, this causes the system to turn up the gain at those frequencies and produce a corresponding noise we know as tinnitus.
  
  
• When a sound is heard which has a deficit around the tinnitus frequencies, the balance is disturbed even more, and this can cause even more tinnitus. With the common high frequency type of tinnitus, such an exacerbating sound would lack the high frequencies and be described as 'muffled' or 'droning'.
  
  
• Anything that disturbs the balance will increase the tinnitus, including feeding in too much of an otherwise appropriate detinnitising signal. Such a signal should therefore be set at a volume only just sufficient to replace the missing content.
  
  
  LEVELS OF AROUSAL… the "Ascending Reticular Activation System".
  
  
• Commonly abbreviated to "ARAS", this is a reticular or 'net-like' structure in the brain-stem that controls our level of wakefulness and attention to the outside world. Its state of arousal often has a bearing on tinnitus.
  
  
• As we go through the day, our arousal level changes according to our activity level and the degree of our immersion in various tasks. This is most obvious when we are waking up or when preparing to go to sleep.
  
  
• The tinnitus often seems most active at a level some way down from peak alertness. So we hear it most at bed time, or when we are relaxing with not much else going on.
  
  
• At these times the tinnitus can be hardest to reach with the Detinnitiser. It is not known why. One could speculate that the brain prioritises external stimuli less as the level of arousal becomes lower. This is a selective effect though. A mother sleeping in a noisy environment can be awoken by the cry of her child.
  

The danger with my 'theory' of Detinnitising is that it is too simple and mechanistic. Various systems, like the ARAS above, and the Parasympathetic Nervous System (PSNS) can have an impact on tinnitus, as can the content of the bloodstream. It gets complicated!

Like all our senses, the sense of hearing can be viewed as an integrated system. This means that the full experience of hearing only emerges when all the levels of processing are activated together. This processing is performed in successively greater depth as the signal proceeds from cochlea to cortex. The precise boundary and location of each processing level is not fully known and indeed each level may well shade into the next. However, on the diagram below, to make things as clear as possible I've posited some possible levels, and related them to various structures in the ear and brain:

(1) Raw signal pick up, direction, pitch, appropriate arousal level determined, frequency analysis (RED on diagram).
(2) Emotional associations (GREEN on diagram).
(3) Understanding meaning of the sound through the use of memory and reasoning (BLUE on diagram).

The question then becomes how can we keep all the processing levels occupied at once for maximum tinnitus suppression? Well, residual inhibition pulses should keep things busy at level 1. Since tinnitus is exacerbated by tension, cultivating a relaxed frame of mind will be beneficial at level 2. Finally, having to deal with to information-bearing sound content (and particularly so, it seems, when this is restricted to lie within the tinnitus frequency band) will keep processing level 3 occupied.

When all these levels are engaged simultaneously, the tinnitus literally cannot be heard. Detinnitising is the only method that is based on this theory.

If you look at the description of the hearing system further up, you'll see our experience of hearing emerges from many different levels of processing all working together in tandem. As a result, it can be difficult to distinguish between how bad the actual 'source' sound of tinnitus is, and how much the level of awareness of it is the crucial factor determining its perception. The sensory and the perception aspects both have a part to play when we 'hear' something. The two are inextricably entwined.

Tinnitus may be very distressing, but it certainly is fascinating! The actual process inside the hearing system that produces tinnitus is not well understood. The cochlea contains a multitude of tiny hair cells which respond to sound waves, alongside cells which can convert nervous signals back into minute sounds. These two types of cells are apparently connected through a feedback system, whose gain is regulated by the brain. Apparently, this system is normally adjusted to operate just below the level of oscillation. But if something gets damaged, it's easy for this delicate adjustment to be disturbed, resulting in the oscillation we call tinnitus.

This would neatly explain why tinnitus often accompanies hearing loss in the same band of frequencies. The system turns the volume up too much to compensate for loss of input. But one of the mysteries about tinnitus is why sounds of different types can both exacerbate and reduce tinnitus.

In the case of my own high-pitched tinnitus, high-pitched sounds will reduce it but "droning" sounds (in effect containing a broad spread of lower tones) can increase it. To account for this, we might surmise that the system always tries to adjust itself to achieve a balance of frequencies over the entire range. Now this balance is already disturbed by the existing dead spot, or deficiency, at the high frequencies, which causes the system to turn up the gain and produce the tinnitus oscillation. When a droning sound is fed in, this balance is disturbed even more, causing even more tinnitus. However, it's not a simple as this. Other factors can exacerbate tinnitus too. Please read on...

To look more deeply into this, I first examined my own unwelcome 'T' visitor!

I found my tinnitus improves with:

• Social engagements & using the telephone.
• My teeth crunching on something.
• Standing up.
• Detinnitising sounds.
• Ginkgo Biloba (NB: use of this can be dangerous).
• ¼ tablet (75mg) of Aspirin daily (NB: this can cause stomach problems).
• Relaxation.
• Full stomach.
• Chocolate.
• Ear cooling with a cold flannel.
• Hearing amplification.

My tinnitus worsens with:

• Heavy (hearing) system processing load (such when listening to music I like).
• Concentration on an intellectual or dexterous task.
• Lying down, preparing to sleep.
• Just after a daytime nap.
• Strenuous exercise.
• Droning sounds, computer fan, and the noise inside my helmet when motorcycling.
• Feeling tense.
• Empty stomach.
• Bashing my ears (!)
• Forcing my jaw forward.
• Certain locations in my home (this is most odd).
• Starchy or diary foods.
• Salty snacks.

Generally, my tinnitus improves when I'm engrossed in something going on in the outside world but is worsened by concentrating on an internal intellectual task. It can be affected either way depending on my posture or jaw position. Also it seems associated with the state of arousal of the parasympathetic nervous system, and it can be improved by agents that reduce the stickiness of the blood. Lastly, some types of sound can make it worse, with others making it better.

So what's the common factor here? Well, all these things (brain activity, posture/localised blood pressure, musculature, diet, digestion, conscious arousal, blood stickiness) either affect or are affected by the blood supply. I would expect an fMRI or PET brain scan to show clear correlations between the changing patterns of blood circulation in the brain and tinnitus. It's unclear whether tinnitus is affected by blood pressure or by resistance to blood flow. In either case, we might expect muscle tension and atherosclerosis to be conditioning factors.

My own tinnitus is central, not heard to one side. So it makes sense to suppose that it is related to the blood supply (its pressure, oxygenation or speed of circulation) at a location beyond where the auditory channels are first combined in the brainstem. However it can't be as far back as the cortex, since then we would expect a cognitive or intellectual aspect to the disorder.

I believe my own tinnitus could be associated in some way with the thalamus. This would tie in neatly with its tendency to be affected by what else my brain is doing at the time and the significance I'm assigning to other tasks. The thalamus is also involved with the regulation of sleep. My tinnitus is at its worst when I am preparing to sleep or have just awoken. Moreover, my tinnitus started after over-intensive massage of the neck. The damage could have been akin to whiplash injury and the thalamus is - sort of - in the right position !  Speculation I know, but interesting.

Here's a guess... Maybe due to atherosclerosis in the blood vessels in the neck, the brainstem running into the thalamus is oxygen-depleted and is generating my tinnitus as a sort of distress signal - rather like pain. But the additional high frequency sound stimulation coming from the Detinnitiser forces this to switch its limited capacity to dealing with real-world sound stimuli, instead of processing the distress signal.

However, the thalamus doesn't just control auditory information going to the brain, it handles most of the other senses too and these are not affected. If my 'theory' is to be sustained, the seat of the tinnitus is likely to lie just below the actual thalamus, where the brain stem could be susceptible to trauma from the neck manipulation which I received just before the onset of my tinnitus, from chiropractic massage. So... the dorsal cochlear nucleus anyone ?

Muscle tension could be playing a part when it compresses, or constricts, or provides nervous stimulation to the relevant structures. For example, thrusting my lower jaw forward or masticating tough, chewy food will increase my tinnitus. This could be squeezing the brainstem.

CLASSIFYING DIFFERENT TYPES OF TINNITUS

Moving on now, for convenience I have divided tinnitus into two major classes, namely: front end tinnitus caused by problems at the input end of the hearing system, and back end tinnitus caused by disorders further in, where higher-level processing takes place. Like much of the material here, these are purely my speculations, and are not medically recognised categories. Neither are these categories necessarily mutually exclusive. A person may exhibit a combination of symptoms depending on the damage.

Typically, front end tinnitus can be expected to be...

• caused by exposure to excessive sound levels.
• associated with damage to the cochlear hair cells.
• 'non-reactive' to type of incoming sound and can be covered up by white noise masking.
• might be associated with hyperacusis and other conditions of excessive sensitivity to the level of sound.
• since caused by ear damage, often concentrated on one hearing side only.

Similarly, back end tinnitus is expected to be...

• caused by muscular shock or tension in the neck, blood supply disorders, unknown causes.
• associated with disorders of the hearing processing system, from the cochlea to the auditory cortex.
• 'reactive' to type of sound; can be made worse by masking sounds but helped by sounds which trigger residual inhibition.
• probably not associated with hyperacusis or sensitive to level of sound.
• often central or binaural in perceived origin.

So front end tinnitus is akin to having 'sore hair cells' which have been damaged by loud sound. The hair cells lie at the start of the hearing system. Front end tinnitus is therefore an input stage disorder. The damaged cells are giving out a distress signal in the frequency band they can no longer handle. That's why tinnitus is so often accompanied by a 'dead patch' in auditory response occupying the same band of frequencies.

Whereas front end tinnitus can be covered up by a masking sound, back end tinnitus will remain just as audible regardless of how loud the masking sounds are. This type of tinnitus can even appear to be competing with the incoming sounds! So back-end tinnitus is a disorder at the processing level of the hearing system rather than the input level. Think of like this. If you were to have a dodgy connection in a loudspeaker lead, you'd get a crackle that would always sound as loud (or as quiet) as whatever signal happened to be passing through, and which it was interrupting. It's the same principle at work with back-end tinnitus. The disorder lies someway down the chain.

So, when sound therapy uses a special noise to discharge this type of tinnitus, its effectiveness will depend on the nature of that therapy noise - not on its loudness. A quiet sound of crickets or cicadas (say) can help, but the loud roar of a motorcycle engine may not.

Back-end tinnitus could require a more subtle sound therapy, using a specially tailored signal that assists in the processing of sound and fills in the finely detailed high frequency component which the hearing processing system is lacking (and seems to be straining for) in such cases.

Back-end tinnitus seems to be heard alongside - rather than under - the sounds of the outside world, since it can be equally well heard regardless of the volume of ambient sounds. For example, while I can hear it over the noise of a loud fan, it is still no louder when heard over silence. It's as if, when the brain is receiving a featureless background noise, it reacts by turning up the gain (and with it the tinnitus) to seek out any information-bearing detail that otherwise would be hidden. In contrast, the detinnitising sounds are full of fine detail, and the brain turns the gain down !

I've noticed the level of my tinnitus is heavily conditioned by what else my brain is doing at the time, to the extent that when it's fully alert and dealing with the outside world the tinnitus is as good as gone. I therefore reasoned that the tinnitus requires brain processing power to be 'heard' but this processing capacity can be set to more productive work elsewhere. This could be one of the reasons that detinnitising works. The brain capacity normally devoted to the tinnitus is instead kept occupied with processing the output of the Detinnitising !

So an effective detinnitising sound is not related to its volume level, but rather its content. This indicates to me that my own tinnitus is of the back-end type and is a disorder of the processing aspect of the hearing system rather than being simply an unwanted 'noise' present at the input.

At this point, a word about the so-called 'phase-cancellation' tinnitus therapies seen elsewhere. Some people claim that tinnitus can be removed in the same way a sound wave can be cancelled - by exposing it to another sound wave in opposing phase. This is not true. Phase cancellation only works with waves. Waves only exist in the outside world - they do not serve any function inside our ear/brain system, at least beyond the cochlea. Tinnitus is NOT a sound wave, it is an internal nervous stimulus that is interpreted by the brain as sound. Therefore it cannot be cancelled by a wave. However it can be cancelled by another nervous stimulus. So, phase-cancellation is out, residual inhibition is in. Detinnitising uses residual inhibition.

THE PRINCIPLE BEHIND DETINNITISING

The principle behind Detinnitising (in its simplest form) is something called 'residual inhibition'. If you've ever tried crumpling an empty crisp packet and found it changes or reduces your tinnitus for a short time this is an indication that detinnitising could work for you too. Why ?

Analysis of the sound produced during crumpling a bag shows an even distribution of harmonics, ranging all the way through the audible range of frequencies up to around 40KHz in the ultrasonic band. White noise (commonly used by tinnitus maskers) also exhibits this characteristic. However unlike white noise, the sound of the bag is also discontinuous. As a general principle, a discontinuous or 'changing' stimulus is required to trigger the body's senses.

Whereas the sound of a masker may eventually be suppressed by the brain (hopefully taking the tinnitus with it), detinnitising sounds attack the tinnitus at source by continually replenishing residual inhibition. This is the effect whereby certain sounds can de-sensitise the ear to the tinnitus and provide relief for a short time - usually for less than a minute. Detinnitising pulses continually replenish this residual inhibition with tiny bursts of sound so short they sound like a series of clicks - many times a second !

Similarly, listening to a burst of high pitched tone of comparable pitch to the tinnitus will also give some relief, though - like the crisp packet - it doesn't last long. Continuing this tone for longer, can actually irritate the tinnitus. The tone must be pulsed or interrupted to work at all. The tone bursts produced by the Detinnitiser are very short (a few milliseconds) long. The frequency of these tone bursts is called the burst frequency. The latest Detinnitiser replaces simple tone bursts by a complex sound formulation.

During development of the Detinnitising method, I found that it was possible to repeat the high frequency bursts in such small doses that they are barely heard as 'beeps' at all, but rather as faint clicks or 'puffs'. This sound is far less objectionable than playing longer bursts of tone and is even more effective. If you view the signal produced by the device on an oscilloscope, you'll see part of it is a compound array of two square waves. One characteristic of square waves is that they're rich in (often inaudible) harmonics - just like the crisp packet !

One might imagine that the tiny high-note hair cells in the cochlea are being given a good old 'work out' and that this exercise somehow reduces the tinnitus. Or that the tiniest hair-cells have got 'gummed up' and detinnitising frees them off. Or perhaps the special sound made by detinnitising keeps the part of the ear/brain reserved for processing the tinnitus 'too busy' to hear it. For a better explanation of this, see the top of this page.

But it must be obvious by now that I really don't know - I can only guess - and that it is an engineer writing here - not a doctor !

The principle behind detinnitising is to 'bottle' the active ingredients of sounds found to be beneficial and repeat them endlessly - in as unobjectionable a form as possible. Out goes the screeching tinnitus, in its place comes an enhanced version of real-world sounds supported by the faint detinnitising 'puffing' sound.

DETINNITISING IN ACTION

If the 'crisp packet' test or the sounds off this page change or reduce your tinnitus then detinnitising may well work for you. If you suffer from substantial hearing loss you could find detinnitising less effective, at least when the unit's volume is turned down.

As regards safety, the CD must not be played too loud. Although the Detinnitiser (device) contains safety limiting and cannot really be abused, as regards the Detinnitising CDs I advise you not to leave them playing at high volume or right up to your ear with headphones. Also, please don't upset household pets with it. So far, the only pet it has been tested on is Dennis the cat - who is totally unbothered !

If your tinnitus is bad, it's often a good idea to start with the detinnitising sound well turned up to start, then reduce it until the 'detinnitising' effect is just maintained (and you can probably only barely hear the device working). Since tinnitus is often at its worse when the environment is quiet and you're on your own, you might wish to reserve its use for these situations.

My own tinnitus is always much worse late at night and when I lie down in bed. I have found the pulsed Detinnitiser sounds from the CD are less effective at this time. Although giving my ears a 'blast' can still deliver relative silence as I fall asleep, leaving the sounds on overnight will not remove the tinnitus when I awake the next morning. However I've found that using the new Detinnitiser (device) can indeed remove this tinnitus at this time.

WHAT EFFECT WILL DETINNITISING HAVE ON 'HABITUATION' ?

Habituation is the process of getting used to the tinnitus until the brain suppresses it, at quite a deep level of awareness. Having used my various Detinnitiser models on and off (only when my tinnitus is at its worst) for eight years now, I'm convinced its effect on habituation has been positive. It seems likely that this is because it gives the brain a 'replacement' (external) 'tinnitus' to get used to; though the sound of the Detinnitiser is far, far easier than real tinnitus to get used to - so it could be a 'short cut' to habituation. I always sleep soundly when it's playing.

WHAT DETINNITISING IS NOT

It is not a 'cure' for tinnitus. It is not a long-term course of treatment for tinnitus. After the detinnitising is switched off the tinnitus will return, maybe after a delay. It isn't a medication or a medical product. Neither is it a 'relaxation aid', nor does it use tapes to take your mind off the tinnitus. It is not a masker - rather it's a tinnitus 'replacer'. It can reduce your tinnitus effectively, but only while it is being used.

CONCLUSION

Well that's it. I hope you can see the tinnitus is a difficult subject, still poorly understood, and I may well have introduced inaccuracies here by attempting to over-simplify it. However, when I first 'caught' tinnitus in 2003 I found I had nowhere to turn for a solution except myself. The Detinnitiser is what has resulted and I can honestly say it has provided me with a useful escape. I hope it can do the same for you.