White noise … pink noise … red noise … brown noise … it is straightforward to get lost in the jungle of sound therapies if we do not take care, upstream, to clear all these notions. These types of treatments, which have been around for 30 years, may seem attractive when trying to reduce the presence and perception of tinnitus symptoms. Although their supposed effectiveness now gives them a real alternative status to be taken seriously, the fact remains that large-scale scientific studies are lacking in this area. However, because of the relative notoriety that they have acquired during the last three decades, it seemed appropriate to make an inventory on the subject. It will be interesting to discover how a white noise generator works and how this type of equipment intends to mask tinnitus. Also, how this form of therapy can speed up the process of habituation, a phenomenon that is known to play a significant role in the treatment of tinnitus symptoms.
What is a white noise generator?
It is a device that can be in different forms, more or less miniaturized. Conventional white noise generators are similar to portable radios that can be moved around easily so they can be used anywhere in the house.
The miniaturized versions of the generator are, for their part, similar to hearing aids that tie directly on the ears.
It is also interesting to note that white noise can also be used via an MP3 player, a smartphone, or even a simple CD player. However, it should be kept in mind that these formats “without apparatus” require some precautions of use, which we will speak at the end of the article.
In a more original register, some companies market pillows capable of spreading white noise. The latter would facilitate the falling asleep of the tinnitus without disturbing his spouse.
Objective: To achieve the masking of tinnitus
White noise has the characteristic of being composed of all the frequencies audible by the human ear. It is, therefore, as such, a composite sound, continuous and the same intensity that oscillates between 20 Hz and 20 000 Hz, which corresponds to the range of audibility. Specifically, it is possible to compare this type of sound stimulation to the sizzling of a radio, the rustle of television without antenna, or even the sound that produces the audio breath.
It is because it is supposed to include all the humanly audible frequencies that white noise is allowed to act on tinnitus. And this is precisely what this sound therapy intends to achieve, namely to dilute the tinnitus symptoms in a neutralizing acoustic “soup.”
The process of habituation in the line of sight
https://www.youtube.com/watch?v=nKo4jYDO9FQ
The patient who will opt for this type of therapy will be exposed daily, about 2 hours a day for 6 to 12 weeks, to a source of white noise. The key idea is to make tinnitus so drown that the auditory cortex can no longer distinguish it. When this type of result is achieved, it is called habituation.
For more details on the phenomenon of habituation, we invite you to discover our expert subject: Tinnitus: how does the process of habituation work?
The white noise, by its masking and blackout effect, would help to put the characteristic tinnitus frequencies in the background. The latter would gradually become less invasive and less critical, which, in turn, would lead to a reduction of stress, a calming of the neuro-vegetative system, and a rebalancing of the nervous and emotional design. It is essential to keep in mind that this hearing therapy is in no way a cure that would have the purpose of suppressing tinnitus. Beyond an illusory suppression, it is a reduction of perception that is sought, with as a side effect desirable, more or less neutralization of stress and anxiety related to tinnitus symptoms.
A habituation therapy to diminish the aversive connotation of tinnitus
In the 1990s, the neurophysicist Dr. Pawel J. Jastreboff has brought to light a correlation between exposure to neutral noise and a decrease in the aversive connotation of tinnitus.
As a reminder, the term aversive connotation is used to describe a stimulus that generates an adverse reaction. Traffic noise, for example, is an annoying stimulus, but it rarely induces a depressive state. This one is considered to have a minimal aversive connotation. Tinnitus, on the other hand, can cause toxic and even dramatic emotional states. This is why, when tinnitus symptoms are problematic, we speak of high aversive connotations.
Jastreboff has created a particular form of sound therapy, TRT (Tinnitus Retraining Therapy), which makes extensive use of neutral sounds. The idea is to achieve, after several months, that the brain automatically inhibits the nerve signal characterizing tinnitus.
It should be noted that, before opting for any use of white noise, it seems relevant to know the frequency of masking most suitable for the auditory disorder. This would speed up the process of becoming habituated.
The supposed virtues of white noise
We have seen above that the white noise consists of a mixture of frequencies that oscillate between 20 Hz and 20 000 Hz. In addition to this purely acoustic technical characteristic, such a variety diffused continuously with a stable intensity, would possess different virtues that deserve attention.
Soothing and relaxing virtues
The appeasement and relaxation that would be induced by listening to a white noise come from its relative monotony. Indeed, as you can see from the sound sample inserted a little lower, this type of neutral noise does not shine by its originality. And it is precisely this monotonous character that would produce a tranquilizing effect. By helping to rebalance the nervous system, white noise would help to regulate stress, tension, and harmful twitches that negatively impact the lives of tinnitus sufferers. Better, it would induce a virtuous circle that can be conceptualized by the following equation:
Less stress = less aversive connotation = less perception of tinnitus symptoms
Relative discretion
One of the exciting properties of white noise is its relative discretion. Indeed, this type of sound stimuli is largely “depersonalized,” which has the effect of making it almost stealthy for us. It’s not a sound that we listen to; it’s not a sound that requires us to focus on it. On the contrary, the white noise is similar to a background noise, ambient, which tends to fade into our consciousness. Very weakly intrusive and endowed with a weak aversive connotation, it does not cling to the spirit. It allows us to go about our business without worrying about the omnipresent but discreet sound environment.
The occupation of the sound space
When you are in a soundproof room, the silence is such that the least sound wave is automatically captured by our ears, treated by the auditory cortex, and brought illico presto to our consciousness. So much so that no noise can escape us. However, the white noise, because of its masking capacity, tends to occupy part of the sound space. In contrast to the silence in which any stimulus escapes all filtration, the “acoustic soup” created by the white noise will play a role of the filter by drowning specific frequencies such as tinnitus. The idea is to ensure that little by little, the brain no longer pays attention to the tinnitus signal.
Hyperstimulation of the nervous system
Because of its monotony and its omnipresence several hours a day, the white noise installs a kind of boredom that can be called hyperstimulation.
It must be known that our brain needs to be stimulated. But when it is no longer, it creates a kind of disinterest. White noise, progressively installing “acoustic boredom,” will produce hyperstimulation of the nervous system.
Concretely, this means that the disinterest will extend to tinnitus stimuli. Drowned in the field of white noise, tinnitus will be gradually banalized, they will lose some of their aversive connotations, which will have the effect of reducing their salience, i.e., their ability to arise in the foreground of our conscience.
The other two categories of sounds: pink noise and Brownian noise
As a reminder, the “white” noise brings together all the frequencies of the field of human audibility. The “pink” noise, more serious, will present an interesting acoustic nuance. Finally, the noise “brown,” called Brownian noise, will be characterized by frequencies even more severe.
Pink noise
Pink noise is like the hum of an electric transformer. This is a sound whose frequency volume decreases by 3 decibels per octave. Its characteristic is to rest on a reduced acoustic pallet. This type of noise lends itself to the ability to restore some acoustic comfort, where the white noise will work more deeply. This is the reason why it would be beneficial to alternate these two variants.
Brownian noise
Also known as “red noise” or “brown noise” by the name of the Scottish botanist Robert Brown which has brought to light what is called the “Brownian movement,” a sound that is distinguished by a decrease of 6 decibels per octave.
It would be more effective in people suffering from hearing loss affecting low frequencies. The use of red noise would also be relevant in case of continuous tinnitus perception of the “engine noise” type.
A therapy that fits over time
You should know that sound therapy using a white noise generator requires a good dose of motivation and high attendance. Indeed, people who opt for this type of treatment must be exposed to this type of stimulation daily (at a rate of 2 hours per day minimum) and this for a period of between 6 and 12 weeks.
Unison Laboratories even mention a minimum treatment duration of 6 months, which makes this form of therapy a demanding treatment to which we must only move if we are ready to invest sufficient time and energy.
What results should we expect?
Although the use of neutral sounds in the context of tinnitus treatment is not, to date, fully validated by the medical and scientific community, it does not seem inappropriate to mention two lessons learned. The first one comes from the Unisson laboratories; the second comes from the 3C Research Federation, which is linked to the CNRS.
Feedback from Laboratoires Unison ™
According to this company, 50% of people monitored would describe a significant decrease in intensity and frequency of occurrence of tinnitus.
Also, it appears that almost one in five people report a complete or near-complete disappearance of their chronic tinnitus.
It should also be noted that according to the laboratories in question, close to one in three people would admit that the therapy had no impact on their tinnitus symptoms, even stating that the tolerance of the latter would be higher.
Note that, pending further scientific studies on the subject, it seems appropriate to consider these feedback with all the caution that is required.
The study conducted by the Research Federation 3C
The 3C Research Federation for Behavior, Brain, and Cognition reported improvement in tinnitus symptoms in nearly one in two patients by the sixth week of treatment.
Note here that it was a therapy using pink noise. Still, according to this federation 3C, it would appear that a re-education using white noise to treat hyperacusis should spread over a minimum period of 12 weeks.
The solution to the equipment
If the use of a mobile white noise generation device is too restrictive, it may be advisable to opt for the installation of a hearing aid that will fit directly on the ear.
For information, be aware that this type of equipment can represent a significant investment: the order of $500 minimum per ear, noting that the cost of this material is not supported by social security.
Some important warnings
Prefer low volume listening
It is essential to keep in mind that this type of sound therapy requires low volume listening, ideally, just above the threshold of hearing. The noise used, whether the latter is white, pink, or red, must never cause fatigue.
Beware of inadequate acoustic quality solutions.
We do not necessarily know it, but the fact is that quite often, some of the white noise generators on the market do not offer the required acoustic quality. Whether it’s CDs, 100% digital media, or mobile devices, beware of poorly sampled formats, MP3s whose compression denatures sounds and soundtracks generated by software whose accuracy is low. It doesn’t seem easy to distinguish by ear an elemental analog breath of a real soundtrack with all the appropriate frequencies. This is the reason why it is better to learn well beforehand, from professionals in the ENT field, before engaging in this type of sound therapy.
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