Tinnitus masking is perhaps the most common form of tinnitus therapy. A masker produces a sound which is matched to the tinnitus signal, resulting in the suppression of the ringing, buzzing sound. A tinnitus masker can provide instant relief by substituting the tinnitus sound with one that is less intrusive, helping patients get to sleep or relax when they would otherwise be distracted.
It is believed that tinnitus masking can lead to long-term changes in the brain, reducing tinnitus intensity and awareness. This process has been termed habituation and is covered in more detail in the Tinnitus Retraining Therapy section.
Development of Tinnitus Maskers
Commercial tinnitus masker devices have been available since the mid-1970s and their development is largely attributed to the work of Dr Jack Vernon, who is one of the founders the American Tinnitus Association and a leading figure in tinnitus research. Being a physician who suffered with tinnitus, he found that when standing in one location near a water fountain, his tinnitus disappeared. He synthesised the sound of falling water and found it to be an effective masker of tinnitus. Before this breakthrough, researchers had neglected the idea that an external sound could mask an internal sound such as tinnitus.
Since Dr Jack Vernon’s early forays into tinnitus masking technology, today tinnitus maskers range from CDs, MP3s and bedside noise generators to wearable devices, hearing aids, and custom-made electronic devices.
Wearable maskers
Around 1974, the first white noise generator was added to hearing aids so that tinnitus masking could occur at the same time as external sound amplification for those that were hard of hearing. These are often known as combination devices or wearable sound generators (WSG).
These WSGs are commonly used by tinnitus sufferers who require masking at all times. A study conducted in 2006 found that patients who used WSGs for 18 months showed significant improvement in self-rated tinnitus loudness when compared to patients who did not use hearing aids or WSGs in the same period [[i]]. However, another study reports that only 30% of tinnitus patients found wearable maskers helpful for tinnitus [[ii]]. Not everyone will benefit from this type of masking, but the 35 to 40% who do benefit, appear to show significant improvement [[iii]].
It is believed that WSGs are ineffective for most tinnitus sufferers, as they cannot reproduce high frequencies essential for masking tinnitus. Most tinnitus sufferers report their tinnitus tone to be above 6kHz, but the small speakers in the device are physically incapable of producing these frequencies. There is an obvious need for improving the high-frequency output of wearable hearing aid devices to improve effectiveness for tinnitus masking [[iv]].
Other wearable maskers include the devices used in Neuromonics, TRT and Tinnitus Phase-Out. These are explored in separate sections.
Tinnitus CDs and noise generators
These are often the most cost-effective and immediate way to get the benefits of tinnitus masking without the need for WSG fitting. They often use one or more sounds described below.
White Noise
White noise is historically the most common sound used for tinnitus masking purposes. White noise is analogous to white light in that it contains all the frequencies of sound in equal proportions. White noise is a great masker and many people find it a relaxing sound to listen to. It is commonly used by people to block out distracting noise and improve concentration. However, some people do find the presence of the highest frequencies harsh on the ear.
There are other shades of noise which are not as harsh that are becoming increasingly popular amongst tinnitus sufferers.
Pink Noise
Pink noise is considered a more natural masking sound to listen to for extended periods. It is similar to white noise, but the highest frequencies have been filtered out, rendering it effective for masking while being comfortable on the ear.
Brown Noise
A sound with a much lower frequency content than pink and white noise, most effective for masking lower tinnitus sounds such as rumbles and roars rather than pure tone ringing. Brown noise is similar to the distant sound of the sea.
Noise Generators
There are numerous desktop/bedside noise generators on the market. The better ones have a range of noise and nature sounds and can normally be timed to turn off. But these devices have one main problem in that their often poorly-produced speaker cannot reproduce the highest frequencies. If you cannot match the frequency of high-pitched tinnitus tones due to ineffective high frequency output, efficient masking will not occur. High frequencies have been demonstrated to be necessary for successful tinnitus masking [[v]].
Your personal “hi-fi” will probably have better speakers than a bedside noise generator, and so a tinnitus masker CD may be a more efficient masking solution. Otherwise, ensure the bedside noise generator can be connected to other playback equipment.
Masking tapes are uncommon today and are inadvisable as the high frequency output of most cassette players is usually about 16kHz, while CD which have sampling rates of 44.1kHZ can reach 20kHz.
Nature Sounds
Most people find the sounds of nature enjoyable and relaxing. The sound of water is particularly popular and well-tolerated. White, pink and brown noise can be thought of as simpler synthetic-sound versions of water as they are similar in frequency characteristics. If you periodically increase and decrease the volume of pure noise, it can sound almost identical to the waves of the sea.
There are a wide variety of nature sound CDs and some of these will lack the high-frequency content essential for masking high pitched tinnitus. In addition, be aware that some nature sounds contain distracting sounds such as bird calls, which although they can add to the overall ambience, can be more distracting than relaxing, especially when trying to sleep.
Music, Radios and TVs
All music and speech evokes a subconscious reaction at a time when the nervous system should be in the absence of acoustic stimulation. Therefore, it is advisable that they are not used for tinnitus masking. Some tinnitus sufferers are told that using a radio tuned just-off station is an appropriate masker. However, Professor Martin Lenhardt of the Otolaryngology Department of Virginia Commonwealth University says that:
‘while the mistuned radio advice has often been offered to tinnitus sufferers, its general utility and long-term acceptance is low’. [[vi]]
[ii] Vernon et al. Clinical measurement. Otolaryngol Clin North Am 36(2):293-305, 2003
[iii] Johnson, R. The masking of tinnitus. In J Vernon (Ed). Tinnitus: Treatment and relief Allyn & Bacon, Needham Heights, MA. 1998. Pp. 164-173
[iv] Vernon et al.. Attributes of tinnitus and the acceptance of masking. Am J Otolaryngol 11(1):44-50. 1990.
[v] Shulman A, Strashun A. Descending auditory system/cerebellum/tinnitus. Int
Tinnitus J 1999, 5(1), 92–106.
[vi] Tinnitus Devices, Encyclopaedia of Biomedical Engineering and Biomaterials, 2004. Martin L. Lenhardt, Professor of Biomedical Engineering, Otolaryngology and Emergency Medicine. Medical College of Virginia, Virginia Commonwealth University.
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