Notched Sound Therapy – How Strong is the Evidence, Really?
Please note: the following information does not constitute professional medical advice, and is provided for general informational purposes only. Please speak to your doctor if you have tinnitus.
For the average person with tinnitus, making sense of the scientific literature on treatments is a difficult task. Without having a background in statistics or the critical appraisal of scientific papers, it’s easy to be persuaded by the efficacy of a multitude of treatments. Navigating this space is made even more difficult by the fact that the internet is flooded with misinformation and marketing copy on treatments that are demonstrably useless.
The tinnitus sound therapy space is a particularly confusing one. You have multiple commercial providers hawking their particular brand of sound therapy, many of them promising significant benefits with studies that show large effect sizes.
Here’s a short list of some of the proprietors available in this space:
- Neuromonics, the most prominent and well known brand
- SoundCure, a new entrant
- Beyond Tinnitus, which was founded by ENT’s
- The Widex Zen, a device purported to provide symptom relief
Each of these proprietors can point to a specific study or set of studies that they claim demonstrates the efficacy of their therapy in treating tinnitus. However, even if a medical experiment has a positive finding with a moderate effect size, there’s still a possibility that’s due to combination of chance and/or experimenter bias. That’s because it’s easier to reach statistical significance for a finding with small sample sizes, and many of the studies done in the sound therapy space have small sample sizes. In general, this is a problem endemic to a lot of research on tinnitus sound therapies. The problem of small sample sized experiments is also one found in the literature on Notched Sound Therapy, the variant of sound therapy I provide.
The other problem with the literature is that a lot of it has an overt commercial influence. So even if you can point to a study (like number 3 in this linked document) many are analogous to a study funded by a drug company trying to bring a particular drug to market. Either a study is funded or run by people with a direct commercial interest in the study outcome (as is the case with a lot of sound therapy research), or alternatively, researchers develop sound therapy with the intent of one day commercializing their invention, which is another form of bias.
The final major limitation of the research on sound therapies is sample selection. The presentation of tinnitus is wildly heterogeneous, with people reporting all sorts of different tones at varying frequencies, producing different types of sounds. Many people have multiple tones, as well. There are lots of individuals who were excluded from these studies because they had tinnitus patterns that were deemed too difficult to treat.
That said, there are a lot of positive anecdotal reports of the efficacy of various sound therapies available on-line. But equally, there are also positive anecdotal reports from things that are obviously useless or entirely placebo-driven, so counting that as evidence is likely not a sound idea. Intuitively, I would like to believe that the anecdotes of efficacy from various different sorts of sound therapies attests to the fact that, through the neuroplasticity of the brain, various methods can be used to remodel the brain’s connections and reduce the subjective volume of a sensorineural tinnitus tone.
I first got tinnitus as a medical student, and in a desperate search for answers, I had a difficult time making sense of the science. It was doubly difficult because, as a person in acute distress, you want to believe all the positive results you read. I eventually stumbled upon Notched Sound Therapy through a professor at my university, which provided me with some acute relief. Fortunately, over the next couple of months I habituated to my tinnitus and didn’t really need any more ongoing therapy, but I realized that there was a gap in the market and decided to start a small business to provide this service to others.
“Notched Sound Therapy” is a term derived from how the therapy is made – you take unprocessed audio such as music or white noise, and “notch out” sound energy at and around the tinnitus frequency of the user. After sustained listening to the customized sound therapy, some small studies have found a modest reduction in the volume of tinnitus experienced by subjects. It’s limited to people who have tinnitus tones that are easily localized by our matching tuner. The mechanism of action isn’t understood, but it’s thought to occur through strengthening lateral inhibition networks between healthy auditory neurons and the aberrant neurons that spontaneously fire, causing the tinnitus percept.
Replication is one of the most important concepts in experimental science. The basic idea is that if an experiment discovers a treatment to be truly effective, then this finding should be able to be replicated elsewhere in the world.
The original research on Notched Sound therapy came out of Germany and the research group of Dr. Christo Pantev. Subsequently, additional research from an analogous (but not identical) form of sound therapy came out of Italy. Whereas Dr. Pantev placed an auditory notch in music and provided this as therapy, the Italian researchers placed a “window” (which, functionally, was a notch) into broadband noise (which sounds like static). Both experimental groups found a positive treatment effect, sometimes large, in their participants. This example of cross verification is why I believe that, for some people, Notched Sound Therapy does indeed work.
Again, the claims of efficacy around Notched Sound Therapy should be modest. It works for some people, some of the time, and seems to provide an average of a moderate effect size in the people that it does help. We have published our internal results here on our blog (choppy and low quality though the data may be, it’s better than nothing).
For a more thorough review of the evidence on the subject, check out this master’s thesis which provides a critical review of the literature on Notched Sound Therapy.
In summary, I’d make the following points:
- Although there are various scientific experiments that appear to demonstrate the efficacy of various forms of tinnitus sound therapy, you should be skeptical about their claims, keeping in mind their small sample sizes and overt and covert commercial influence (this includes my arguments as well).
- It’s important to educate yourself as a patient on how to critically appraise scientific evidence, especially so you can avoid the various outright scams and snake-oil available on the internet. As a general rule, be skeptical.
- There is some evidence that Notched Sound Therapy is efficacious for some people, but as with all sound therapies available for tinnitus, a truly definitive scientific answer is not yet available.
If you’re interested in sound therapy for tinnitus check out AudioNotch.com. We offer a service to treat tinnitus and ringing ears through sound therapy online. If you have any questions feel free to contact us.