Many of us have just spent the Christmas season with a persistent and irritating ringing noise in our ears. But now that the relatives have gone home for the year, it's worth remembering that a large proportion of the population suffers from a more persistent ringing sensation - tinnitus. It happens in the absence of noise, it's one of the most common symptoms of hearing disorders, and it's loud enough to affect the quality of life of around 1-3% of the population.
There have been many suggested treatments but none of them have become firmly established and most simply try to help people manage or cope with their symptom. Now, Hidehiko Okamoto from Westfalian Wilhelms University has developed a simple, cheap and enjoyable way of reducing the severity of the ringing sound. The treatment has showed some promise in early trials and even better, it is personally tailored to individual patients.
The method is simple. Find out the main frequency of the ringing sound that the patient hears - this becomes the target. Ask the patient to select their favourite piece of music and digitally cut out the frequencies one octave on either side of this target. Get the patient to listen to this "notched" piece of music every day. Lather, rinse and repeat for a year.
Okamoto tried this technique in a small double-blind trial of 23 people, eight of whom were randomly selected to receive the right treatment. Another eight listened to a piece of music that had a random set of frequencies cut out of it, while seven were just monitored. The treatment seemed to work. After a year, the treatment group felt that their ringing sensation was around 30% quieter, while the other two groups showed no improvements.
This is obviously a very preliminary study with only a small number of people. Nonetheless, it's encouraging because finding workable treatments for tinnitus has been difficult because until recently, we didn't really understand what causes it. The key point is that it's not a problem with the ears, but with the brain - specifically, the auditory cortex which processes the sounds we hear.
The neurons of the auditory cortex are arranged in a sort of frequency map, with cells that respond to low frequencies at one end and those that respond to high frequencies at the other. Distortions or damage to parts of this map result in tinnitus. This could be due to an injury directed at specific groups of neurons. It could even be due to the gradual hearing loss that accompanies old age.
As the connections between the auditory cortex and other parts of the brain start to wane, some neurons within the cortex stop working properly. But rather than slide into inactivity, they become rewired so that they respond to the same frequencies as their neighbours. Certain parts of the frequency map essentially fuse with one another. Indeed, scientists have found that the activity of the auditory cortex neurons corresponding to the tinnitus frequency is greater than normal, and the more active they are, the more intrusive the ringing is. It's a case of the brain's own flexibility becoming its undoing.
Okamoto's treatment was inspired by earlier work, which showed that you could reduce the activity of neurons in the auditory map by playing people music with the frequency in question removed. It's possible that listening to this music silences the overactive neurons corresponding to the notched frequency. Alternatively, these neurons could be actively suppressed by their buzzing neighbours.
Either way, Okamoto found that the notched music reduced the activity of the affected neurons within the auditory cortex of his patients. These physical measurements matched the patients' descriptions of their own experiences, and the two measures were strongly related.
Okamaoto thinks that getting patients to pick their own favourite music was an important part of the technique. The music we like can grab our attention and triggers the release of dopamine, a chemical involved in feelings of reward and pleasure. It's also important for rewiring parts of the cortex, when our brain needs to be flexible.
Reference: Okamoto et al. 2009. Listening to tailor-made notched music reduces tinnitus loudness and tinnitus-related auditory cortex activity. PNAS doi: 10.1073/pnas.0911268107
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That's interesting. I wonder if the brain goes wonky when hearing is impaired. I noticed some tinnitus when I've had outer ear infections.
I'm one of the 1-3% who suffer from tinnitus enough to affect my quality of life. It's really really unfun. But as it happens, I've actually been using a treatment very like this for years. I have a very high frequency noise, and when I get an attack, I play music with lots of (relatively) low frequency stuff. Or even any music at all.
My friend has five different noises; I wonder how this treatment would work with her?
Also, it's not entirely accurate that tinnitus occurs in the absence of external noise. It is certainly less irritating, and less noticable when there is external noise. However, depending on the type and volume of external noise, I can usually hear my tinnitus anyway. If I actively listen for the noise, I can usually pick up on it.
It is actively exacerbated by certain kinds of noise as well. I especially avoid external noise of frequencies near what I hear in my head, as that often encourages or triggers an attack. I have more than one cowered in corners with hands over my ears humming frantically as the neighbour mowed the lawn.
I can also not bear to be in a house with a tv on standby. It makes a noise that I can hear through three walls and it's completely unbearable.
I've got some damage in the left ear which gives me a little bit of tinnitus. It's not bad and I can pretty much ignore it now.
At some point I need to do something about it though. Either a CI or the new laser treatment to fix the screwed up conduction mechanism in that ear would be good.
I wonder if wearing a hearing aid type device that would filter out the surrounding octaves for a prescribed time each day would help-- so that the targeted frequencies would be eliminated from whatever sound was going on. Except singing in the shower!
This is really interesting. I have pretty constant but low-volume tinnitus (it's only really noticible if it's quiet, but I can hear it most of the time) that has a range of frequencies (all of them quite high). If this proves to be a viable treatment, I hope it is as inexpensive as it seems like it ought to be. A whole cd of frequency-deleted tracks would be even better, just from a listener's point of view--you could choose a new one daily, so there'd be perhaps 2 weeks' worth of songs rather than just 1 (listening to a song 26 times a year instead of 365 sounds excellent).
I would love to try this technique. Do you have any suggestions for how to digitally remove frequencies from a piece of music?
Really nice advance I want to try, i think all of us want it. Do anybody knows how to try the treatment? How to find the exact frecuency of the tinnitus? and how to remove the frecuency from the song? I have tried with some software but i feel i am wasting time, somebody can help?
Iâm a practicing psychologist who happens to suffer from tinnitus. Iâve spent a lot of time dealing with my own tinnitus, and helping other people deal with theirs. I am guardedly optimistic at the prospect of a treatment that can reduce the ringing. If this really does reduce it, then that would be terrific. At the same, I think that a large part of tinnitus-related impairment is related to the anxiety and anger that result from attempts to AVOID the ringing in our ears. Personally, I have found that applying cognitive-behavioral principles and practicing mindfulness meditation have been incredibly helpful to me. I still hear the noise all the time, but I am much less frequently annoyed or anxious about it than I used to be. So, until this technology is widely available, it might be helpful for folks to try CBT and mindfulness approaches.
You have broaden my knowledge regarding tinnitus. It explained
well and elaborate the causes and effect. Hope to
read more about these symptom. thanks
IntÃ©ressent, en effet attention tout de mÃªme pour les gens sensibles aux bruits, aux hyperacousies, a la qualitÃ© du son Ã©coutÃ© et aux autres personnes qui mettent encore le son trop fort, j'en avait dÃ©jÃ entendu parler sur le site http://www.traitementacouphene.com quand je m'Ã©tais inscrit, je trouve que sa se rapproche fort de la TRT.
En tout cas merci pour cette article, et bonne continuation pour le blog.