It's probably no surprise to you, but noise levels have steadily risen over the years. The reason? Primarily, technological advances. Walkmans, loud stereos, clattering computer printers, more jet aircraft and heavier traffic levels are all contributing to the increase in noise all around us.
And it's of ever-growing concern, because noise of one of the leading causes of hearing loss.
Sound is produced by the movement of air molecules generated by a vibrating object. The intensity of the vibration, or loudness, is measured in units called decibels (db). For example, a soft whisper registers about 20 db; while an air-raid siren measures as high as 140 db.
Sound vibrations are channeled into the ear canal to the eardrum. The eardrum vibrates, and the vibrations travel through the bones of the middle ear to the fluid inside the cochlea of the inner ear. Inside the cochlea are thousands of tiny hair cells and nerve endings which transfer the vibrations into nerve impulses, which are sent to the brain.
When a noise is too loud, it can damage the hair cells within the cochlea. And as exposure to loud noise increases, more and more of these hair cells are damaged, resulting in a decrease in the quality of hearing. And when damage is severe, hearing loss is permanent.
More than 8 hours exposure to 90 decibels can cause a temporary hearing loss. Two hours at 100 db can mean some permanent hearing loss. At 120 decibels, some of the sensitive hair cells in the inner ear that transmit sound will be immediately destroyed. And that means irreversible hearing loss.
If you're a frequent - or even casual - air traveller, you know what we mean. On take off or descent, pressure can build up inside your ears, you can't seem to "pop" them, and the discomfort can build to become downright painful.
Considering that today's jet planes travel at altitudes of thirty to forty thousand feet - where air pressure is significantly less than at sea level - it's easy to understand that the difference between the pressure in your head and the pressure in the airplane cabin can present problems, in spite of pressurized cabins.
Ear discomfort while flying is a very common problem, and here are a few simple tips that may prevent or reduce ear problems for you :
In two words : avoid it. Or at least minimize prolonged exposure to loud noise. If you're exposed to it in the workplace, wear ear protestors or ear plugs.
For the office or home, bulky furniture, heavy carpeting and thick drapes help muffle sound.
And for the rest of the world, many people are looking to local government to curtail unwanted noise. Contact your local city officials about noise ordinances and what you can do to help get them enacted.