The damage from excessive noise exposure is permanent; there is no way to restore life to dead nerve endings.
Lorraine Seabrook
Hearing loss is a painless and gradual process that often takes people by surprise.
Of the nearly 30 million Americans who suffer from hearing loss, many do not realize that they have this medical disorder until they have trouble understanding what people are saying or notice a ringing sound in their ear (tinnitus).
If you find yourself asking people to repeat themselves, this could be the beginning of high-frequency hearing loss, which is easily detected with a hearing test. A ringing or other sound in your ear is often the result of long-term exposure to noise.
Dr. David Goldfarb, chief of the Otolaryngology Department at University Medical Center at Princeton, answers questions about the most common cause of hearing loss exposure to excessive noise.
What happens if noise is too loud?
When noise is too loud, it begins to kill the nerve endings in the inner ear. As the exposure time to loud noise increases, more and more nerve endings are destroyed. As the number of nerve endings decreases, so does your hearing. The damage caused by noise, called sensorineural hearing loss or nerve deafness, can be caused by several factors other than noise, but noise-induced hearing loss is different in one important way it can be reduced or prevented altogether.
Is this damage temporary or permanent?
The damage from excessive noise exposure is permanent; there is no way to restore life to dead nerve endings. Once hearing is damaged by noise, there is no treatment that completely restores your hearing.
How can I tell when noise is dangerously loud?
As a general rule, noise may damage your hearing if you have to shout over background noise to make yourself heard, the noise hurts your ears, it makes your ears ring, or you have difficulty hearing for several hours after exposure to the noise.
Does the length of time I hear a noise have anything to do with the danger to my hearing?
It certainly does. The longer you are exposed to a loud noise, the more damaging it may be. Also, the closer you are to the source of intense noise, the more damaging it is. Recent studies show an alarming increase in hearing loss in youngsters. Evidence suggests that loud music along with increased use of portable radios/CD players with earphones may be responsible for this phenomenon.
How is sound measured?
Sound can be measured scientifically in two ways: frequency cycles per second (Hertz or Hz) and intensity or loudness of sound (decibels or dB). The higher the pitch of the sound, the higher the frequency. Young children, who generally have the best hearing, can often distinguish sounds from about 20 Hz, such as the lowest note on a large pipe organ, to 20,000 Hz, such as the high shrill of a dog whistle. Human speech, which ranges from 300 to 4,000 Hz, sounds louder to most people than noises at very high or very low frequencies.
Decibels measure intensity or loudness of sound. The scale runs from the faintest sound the human ear can detect, labeled 0 dB, to over 180 dB, the noise at a rocket pad during launch. Decibels are measured logarithmically. This means that as decibel intensity increases by units of 10, each increase is 10 times the lower figure. Thus, 20 decibels is 10 times the intensity of 10 decibels, and 30 decibels is 100 times as intense as 10 decibels. Many experts agree that continual exposure to more than 85 decibels is dangerous.
What are some sure signs of hearing loss?
When hearing impairment begins, the high frequencies are usually lost first, which is why people with hearing loss often have difficulty hearing the high pitched voices of women and children. Loss of high frequency hearing also can distort sound so that speech is difficult to understand even though it can be heard. People with hearing loss often have difficulty detecting differences between certain words that sound alike, especially words that contain S, F, SH, CH, H, or soft C sounds, because the sound of these consonants is in a much higher frequency range than vowels and other consonants.
How can I protect my hearing?
The most effective way to protect your hearing is to avoid excessive exposure to loud noise. Wear quality ear protectors if you must work in an excessively noisy environment; when using power tools, noisy yard equipment or firearms, or when riding a motorcycle or snowmobile. Ordinary cotton balls or tissue paper wads stuffed into the ear canals are very poor protectors, reducing noise by approximately 7 dB.
What should I do if I suspect hearing loss?
If you have symptoms, you may have nothing more serious than impacted wax or an ear infection, which might be simply corrected. In any case, take no chances. Make an appointment with an otolaryngologist or otologist who can diagnose your hearing problem and recommend the best way to manage it.
For more information, visit www.princetonent.com.