All About Noise
	Dr. Nathan Jacobs
Q	What percentage of all hearing loss or impairment is estimated to result from noise exposure?
A	We know from population studies that about 10 percent of the population of the United States has an impairing hearing loss. We also know that noise exposure causes more hearing loss than all other causes combined, but just what the percentage would be has never been really determined. I would suspect that it would be about 50 percent of the hearing loss that occurs in the general population.
Q	What are some examples of noise intrusions that have actually damaged hearing?
A	We certainly know that gunfire as experienced in military combat will do this. We also know that noises above 85 dBA in industry, with long exposure, will cause hearing loss. Sudden noises such as a fire cracker exploding near an ear can also cause a hearing loss, and sometimes if a single gunshot is fired close to an ear it can cause total loss in that ear. This doesn't happen all of the time, but it can happen, Dr. Aram Glorig, head of the House Ear Institute's Noise Research Center, has expanded knowledge about the effects of noise on hearing, with over 40 years' leadership in the field.
Q	Does the average person have much to worry about?
A	In a highly mechanized society where we are exposed to all kinds of industrial noises, as well as recreational noises, the general population does lose some hearing over a long period of time, in addition to that which occurs from aging only. For example, some household appliances, such as lawnmowers and vacuum cleaners, can cause a hearing loss if they are used over long periods of time. Any type of loud vehicle can produce hearing loss if it is used often and long enough.
Q	Can a one-time exposure to an unexpected, extremely loud, painful noise cause damage?
A	Yes. This can cause damage at times, but there are also times when it does not. It depends upon the circumstances and how close the loud noise was to the ear and whether or not it occurred in an open space or in a closed area.
Q	What level of exposure causes permanent damage?
A	We have determined by a considerable amount of research that any level above 85 dBA can cause permanent damage again, depending upon the level of exposure. Obviously, as you increase the level, the time to cause the loss will be shortened.
Q	Does it just seem that our society is becoming noisier or is there documentation of actual increases?
A	Actually, there is no documentation that noise levels have increased, but we do know from our research that noise exposure is much more widespread now than it used to be because of the increase in population and because of the increases in noisy types of transportation, etc.
Q	Are today's youngsters losing hearing sooner than generations before them? Why?
A	We are finding more hearing loss in teenagers and young adults who are tested, particularly at high school and college age, than we used to 15 or 20 years ago. This is probably because of the recreational activities to which they are exposed, such as loud music and earphones, and all kinds of recreational activities, particularly those that have to do with car or boat racing, etc.
Q	When does hearing usually begin to decline as an effect of aging?
A	Actually, hearing loss begins shortly after birth, but it is not really measurable to any extent until about age 45 or so, then it begins to show up with the kind of tests we do routinely. With aging, the rate of loss increases.
Q	What are some of the warning signs of hearing loss?
A	Tinnitus that is lasting, and which comes on after exposure to noise and lasts for an hour or so before it clears up is a warning sign. Any noise that causes temporary hearing loss into the next day can result in permanent loss if this is repeated often enough When a person complains of hearing men's voices better than women's, it is indicative of a high frequency loss, usually the first type of loss that occurs.
Q	Can hearing loss occur without a person's awareness?
A	Yes, particularly since hearing loss from noise exposure is insidious. It begins in the high frequencies and these do not show actual impairment for some time.
Q	Do you think the increased focus on environmental issues will tie into any increased awareness of noise pollution?
A	I believe that the types of studies that are being done, and the types of laws that are being passed by federal and state governments have increased the awareness of noise pollution considerably in the general population. However, a great deal more education is necessary before it becomes general knowledge.
Q	What steps should be taken to protect ears and hearing?
A	Avoid any loud noise exposure without some sort of ear protection. Any time a person is exposed to noise levels which cause difficulty in communicating, care should be taken to protect the ears. If it is difficult to communicate except in a loud shout, then we know the noise level in the area is sufficient to cause a hearing loss.