Friday, July 22, 2011

Do cell phones cause tinnitus?

Forget about cancer caused by cell phones, what about that ringing in your ear? About 10-15% of the adult population suffer from chronic tinnitus. I've had a case of tinnitus after a back injury. Luckily it vanished after 3 months, but since then I'm very sympathetic to people who go nuts from that endless ringing in their ear. A recent study by a group of researchers from Vienna now looked into the correlation between cell phone use and tinnitus. The results are published in their paper Tinnitus and mobile phone use, Occup Environ Med 2010;67:804-808. It's not open access, but do not despair because I'll tell you what they did.

The researchers recruited a group of 100 sufferers that showed up in some hospital in Vienna. They only picked people for whom no physiological, psychological or medical reason for the onset of their tinnitus was found. They excluded for example patients with diseases of the middle ear, hypertension, and those medicated with certain drugs that are known to influence ear ringing. They also did hearing tests to exclude people with hearing loss, of which one might suspect that their tinnitus was noise induced. Chronic tinnitus was defined as lasting longer than 3 months. About one quarter of the patients had had it already longer than 1 year at the time of recruitment. 38 of the 100 found it distressing "most of the time," and 36 "sometimes." The age of the patients ranged from 16 to 80 years.

The researchers then recruited a control group of also 100 people that were matched to the sufferers in certain demographic factors, among others the age group, years of education and whether they lived in- or outside the city.

At the time the study was conducted (2004), 92% of the recruits used a cell-phone. (I suspect the use was strongly correlated with age, but no details on that in the paper). At the time of onset of their tinnitus, only 84% of the sufferers had used a cellphone, and another 17% had used it for less than a year at that time. The recruits, both sufferers and controls, were asked for their cell phone habits by use of a questionnaire. Statistical analysis showed one correlation at the 95% confidence level: for cellphone use longer than 4 years at the onset of tinnitus. In numbers: In the sufferer's group, the ratio between those who had used a cellphone never or less than one year to those who had used it more than 4 years was 34/33. In the control group it was 41/23.

They then discuss various possible explanations, such as the possibility that cell phone radiation affects the synthesis of nitric oxide in the inner ear, but also more banally that a "prolonged contrained posture" or "oral facial manoeuvres" affect the blood flow unfavorably. (Does chewing gum cause tinnitus?)

The result is just barely significant, i.e. just at the edge of the confidence interval. There's a 5% chance of that result happening just coincidentally by unlucky sampling. So the researchers conclude very carefully that "high intensity and long duration of mobile phone use might be associated with tinnitus." Note that it's "associated with" and not "caused by." Needless to say, if you Google "cell phones tinnitus" you'll find several pages incorrectly proclaiming that "The researchers concluded that long term use of a mobile phone is a likely cause of tinnitus," or that the "study suggests cell phones may cause a chronic ringing in the ears." If such a Google search lead you here, the study concludes nothing of that sort. Instead, the authors finish with saying that there "might" be a link and that the issue should be "explored further."

So, do cell phones cause tinnitus? Maybe. Should you stop sleeping with the phone under your pillow? Probably.

In any case, I was left wondering why they didn't ask for phone habits generally. I mean, if it's the posture or movements connected with calling, what's it matter if it's a cell phone or a landline?

21 comments:

Phil Warnell said...

Hi Bee,

Interesting, as I have had a cell phone for more than 15 years and since getting one experienced ringing in my ears; however it does stop the moment I press the talk button :-) More seriously, I’m astounded by the bad rap cell phones are getting and even more significantly the increased number of people I encounter who are concerned by all the microwaves that are being produced by the phones and the towers that facilitate their use. When I ask them if they are aware that the entire universe is awash in microwaves, many have responded , “it’s the oscillations of the waves that’s the problem” . So in other words they attribute it to being not the media but rather the message. I can only suppose it hasn’t bothered me as resultant of being hard of listening, rather than hard of hearing;-)

Best,

Phil

Bee said...

Hi Phil,

Ha. Not sure whether I should laugh or cry. This now makes me wonder if not somebody has a download that makes your cell phone emit radiation that cures migraine/influenza/cancer? If it's nonsense, why does it have to be depressing in addition? Best,

B.

Christine said...

sleeping with the phone under your pillow

People who do that need help.

Best,

Christine

Phil Warnell said...

Hi Bee,

We must laugh or we to will go insane and the reason for that was given years ago by a humourist, rather than a doctor or a scientist.

“Everything human is pathetic. The secret source of humor itself is not joy but sorrow. There is no humor in heaven.”

-Mark Twain

Best,

Phil

Christine said...

BTW, nice that you put a picture of Capt. Kirk. Ah, Star Trek, the Original Series... Even with eventual scientific flaws, & other well documented problems (for those who read about the making and all the story behind know what I mean) it was the best TV show ever. Automatic opening doors, communicators (cell phones), medical scanners, disquettes and pads... They had an idea of the future, they consulted NASA. Now we need the transporters and a ship to travel the galaxy wrapping the spacetime continuum in order to overcome the velocity of light... Ah... maybe we will never have the latter. :(

In any case, Spock with those ears didn't suffer from tinnitus, eh eh... So we have a hope for the future here as well. :)

[But did you know that the actors (Leonard Nimoy and William Shatner) do have tinnitus? It was caused from an explosion in the stage, while shooting an episode.]

Best,
Christine

Phil Warnell said...

Hi Christine,

I been told by many who do that it’s because they believe that every once in a while the Microwave fairy will drop by to exchange their old phone for a new one :-)

Best,

Phil

Plato said...

The Mrs. here and I were just talking about that "ringing in the ear thingy" yesterday in terms of her ears. I told her it was the background noise of the universe:)

Seriously here were some thoughts on my mind.

Best,

Plato said...

Problem is, she texts lots to the family.....but does the mobile phone have to be that close? I know for a fact it doesn't as it's range can be in terms of "let's ten feet" and still is powerful enough to make a connection:)

The reason I brought it up with her was I was hearing a high pitch sound myself(knowing she has this problem)...wondered where it was coming from....I located the source and it wasn't the cell phone. Electricity when gathered in "a light source" can be quite noisy?

Got to check it out.

Her ears were still ringing though. Hmmmmm.....Cell phone towers can be extremely noisy?

Best,

Uncle Al said...

Do a study that uncovers cellphone use eliciting carnality, especially amongst teenagers. That will get them banned double quick, certainly in the US. Anything emerging from the Evil IQ that is useful and pleasurable must be banned. God says, "those who sup from the Tree of Knowledge will be expelled from Eden."

OTOH, conspire with your peers to set your cells to "vibrate," then reach out and touch someone. Moral authorities will go ballistic. Sin like you mean it.

Steven Colyer said...

Regarding Phil's first comment in these replies, yes it is aMAZing to me the low quality of even basic science knowledge in the US. I cannot recall a single bad Math or Science teacher in grade school or high school, and most of the problem teachers were History. Problem is, Math and Science becomes "optional" for too many after the first year of high school and many don't ever study those subjects again. Does one need to know Science to watch "Dancing with the Stars" or "Tosh.0"? I think not.

My favorite is the "microwave radiation" from above ground high power lines. Oh good grief. Inverse-square law, anyone? I guess not. Sigh.

So yes Bee you have every reason to get depressed. One can only hope the situation is a bit better in Europe.

Spot on Christine well said re Star Trek:TOS being the best show ever. Roddenberry employed REAL science fiction authors to write the stories, which were of the highest quality. Kids today don't appreciate it because the special effects are cheesy by today's standards, but they were far ahead of anything on television at the time.

Bee said...

Hi Plato,

Well, I hope it isn't too noisy... I think in most cases, it's unclear what causes tinnitus, though some factors are known to contribute, lack of oxygen for example. One article I read recently said the ringing is actually not caused by the ear, but (if I recall correctly) it's a result of the brain trying to compensate for a (temporary) hearing deficit in a certain frequency, a compensation that however fails to go back to normal once the problem has been resolved, leaving a background noise in that frequency range. (Like an afterimage that doesn't want to fade.) They're now basically trying to teach the auditory system to 'not hear' that noise. (Much like you might have learned to 'not hear' the church bells ringing, not because they're not there, but because it's not an interesting signal.) There's apparently several examples of people who had their auditory nerve cut to get rid of the tinnitus, only to be left deaf yet still stuck with the tinnitus! Best,

B.

Bee said...

Hi Steven,

I actually don't know how far spread scientific ignorance is in Europe. It certainly isn't as prominently displayed. I suspect it's a threshold effect at work there. There must be some mean free path that people will go to find another fellow who supports their belief (confirmation bias and all). If they find a next person within their typical social network, they'll reinforce each other and spread ignorance. If not, they'll just sit there on their own. So once you've reached a certain critical density, ignorance gets organized. In any case, the inverse square law is for point sources if I recall correctly. Best,

B.

Steven Colyer said...

Hi Bee, I suppose you are correct given that you're the Physicist and you don't want to know how long it's been since the I studied Maxwell's Equations and their consequenes. I had long hair at the time and I belive Carter was running for President. :-)

In any event, Wikipedia to the rescue! So looking up Inverse-square law I note that sound pressure p follows the inverse distance law 1/r and that with dipoles an inverse cubed law is followed!.

Now I'm thoroughly confused. What I need at this moment is a perfectly spherical cow and a strong cup of Joe, and so I shall.

Plato said...

Without sounding as if supporting "one over another as to bias" the UK threshold(?) the thought still exists as I wondered.

Okay I am ignorant. Logically deduced:)

Steven:My favorite is the "microwave radiation" from above ground high power lines. Oh good grief. Inverse-square law, anyone? I guess not. Sigh.

Oh and yes as to inverse square law and yes too, the approximate of spherical cow. No expert on microwave radiation either, hence the opinion of those better educated:)

Do Cellphones Cause Brain Cancer? However ridiculous the continued question.....as if in context of opinion by Uncle(?), dispel the illusions by a logical discussion as to your proof and reasons and forever let it lie as to scientific fact conclusive. All the science included....instead of acting as a choir for the unreasonable:)

Help me:)

Best,

Uncle Al said...
This comment has been removed by the author.
Uncle Al said...

@Steven Colyer My favorite is the "microwave radiation" from above ground high power lines. Oh good grief. Inverse-square law

A monopole infinite line source is 1/r not 1/r^2. Do the integral. Power lines are US 60 Hz, UHV is DC. You are a microwave source! So is everything else, plus the sun and the universe. Your internal meat is 37 C. Microwave emission tail, to the right.

Most folks prefer one phone ear. Dose and control are performed over billions of hominid-hours/year for more than decade. No pathology is associated with exposure. But what of second-hand microwave exposure and children? Mandatory floating Faraday cages for all until age 18!

Steven Colyer said...
This comment has been removed by the author.
Steven Colyer said...

I think you're an alien, Al (I meant that as a compliment). I think your IQ, your Mensa-ness shall we say, is too large for the rest of us mere mortals. (I meant that as a compliment, too).

I have two immediate goals: First, run your fellow Mensa-ite Neil Bates' experiment, then ... yours.

Running them both would have two clear positives:

1) First, it would settle whether the two of yours are right or wrong.
2) Second, it would get the two of you to STOP talking about two experiments that aren't, quite frankly, ALL THAT EXPENSIVE to run!

I think that would make each of you more popular, and who's to say: The Nobel Prize in Physics, anyone? Maybe, maybe not? Let's you, know ... TEST stuff! It doesn't take a 20 billion dollar project to increase Humanity's knowledge base. Sometimes, a simple table-top experiment, if done right, will do.

For reference:

1) Michelson-Morley
2) Renate Loll et al's Ink blot Experiment re CDT.

Sigh, WHEN will we wake up as a species, and realize that money is NOT everything?! Sometimes, KNOWledge trumps all!

By the way, and other Mensans here? It's not just Neil and Al, is it?

Bee said...

Hi Steven,

Maybe you recall having heard about the 'multipole' expansion. What you do is you take some arbitrary charge distribution and (roughly) describe it as an overlay of various symmetric configurations, monopole, dipole, quadrupole, etc. Each of these terms in the expansion comes with some factors that however can be zero. For a dipole by definition all moments except the dipole moment vanishes, in particular the monopole contribution (which would have the 1/r^2) isn't there. And of course that's for the field - if you look at the potential it's all one 1/r less. In any case, what I was saying is just that not everything goes with 1/r^2, it depends on the charge configuration (the exponent -2 depends on the dimension). The simplest example is the electric field of an (infinitely extended) wire. Best,

B.

Kalle k said...

Help raise money for reasearch into Tinnitus by using the searchengine goodsearch and raise 1pennie with each search you do. Link: http://www.goodsearch.com/?charityid=22689
Youtube video: http://www.youtube.com/watch?v=6XmACVafixo

arshad said...

Hi its really very nice blog,very useful information..Mobiles