Saturday, September 30, 2006

Tinnitus on the rise due to increase in noise levels

It is no wonder that tinnitus is on the increase, especially amongst younger people. Our ears are assailed daily by noise levels that they were not designed to cope with. It is often said that we have a stone-age body in a 21st Century world. Our ears are capable of picking up tiny sounds that were important for survival in the natural world, for example awareness of prey or predators some distance away.

But if you look at the chart below you can see that many every-day noises such as busy city-centre traffic or even a lawnmower can produce noise levels which, if you are exposed to for too long, can cause hearing damage or even tinnitus. If we take more extreme examples such as a rock concert or nightclub then you can see that hearing damage can occur very quickly. It will come as no surprise then to discover that many performers and disc jockeys suffer from hearing loss and tinnitus.

The chart shows noise levels measured in decibels (abbreviated dB) so here is a brief explanation for anyone unfamiliar with the terminology. The term actually comes from the name of the inventor of the telephone, Alexander Graham Bell, and the measurement has to take account of the huge variation in intensity of the range of sounds we can hear. So if we take a really quiet sound like a watch ticking or leaves rustling and compare with a loud jet like Concorde at takeoff, then the difference in the power of the sounds is about 1,000,000,000,000 times!

So on the decibel chart, 0dB is near total silence but 10dB is ten times more powerful and 20dB is 100 times more powerful, 30dB is 1000 times more powerful, and so on. A hairdryer at 80dB is one hundred times as loud as normal conversation at 60dB. A rock concert of 120dB is a million times as loud as normal conversation.

Any noise above 80dB can cause hearing loss and the loss is related to the power of the sound and the length of time you are exposed. It is no accident then that from February 2006, the new noise regulations lower threshold for the workplace, when ear protectors must be made available, is reduced from 85dB to 80dB. However, legislation will not apply to the music and entertainment industries until 2008 so avoid excessive noise if you are off to a rock concert and take earplugs with you. This particularly applies to existing tinnitus sufferers. Earplugs can improve the clarity of the sound in these conditions and make conversation easier.

Any exposure to noise above 140dB will cause immediate hearing damage.

Despite the risks, it is amazing what lengths some people will go to in order to create deafening sounds. The current fashion is to install stereo systems in cars with more amplification power than the Rolling Stones used to use to fill a stadium. The stereo is probably worth more than the car but we can predict with certainty that the owners will have hearing problems later in their lives.

Diagnostic Approach to Tinnitus

I've found a comprehensive article about Tinnitus diagnostic on a level of doctor of general practice. Few accents: vibratory tinnitus: vibrations from adjacent tissues are transfered to cochlea. pulsating t. arises from vascular disorders: aneurysms, acquired arterio-venous shunts Pulsatile t., unilateral t. and t. associated with other unilateral ear problems speak for an organic cause. Subjective t. (heard by patients only) mostly arises from the same condition as the hearing loss: eardrum perforation, noise exposion... Some other causes: Psychologic, Anemia, Thyroid disorder, Drugs: Aspirin, Gentamycin, Furosemid. Lead, mercury. Multiple sclerosis, nerve tumors. Objective t. (heard with stethoscope): Patients tipically have vascular abnormality, neurologic disease or eustahyan tube dysfunction. Diagnostic: otologic examination, sound tests, audiometry. Blood tests (minerals, cells, hormones), MRI (tumors) Notice: *Not all subjective tinnitus have a psychologic cause.* Read the article.