More Young Lose Hearing : Deafening Din Really Is, Audiologists Warn

After 15 years working around the roar of fire engines and the whine of high-powered equipment, La Mesa Fire Capt. Dick Gaffney began to notice that he was having trouble understanding what people were saying to him.

It wasn’t so much that Gaffney could not hear--or so he thought. But in conversation, he detected vowels while certain consonants slipped by, leaving him to divine a speaker’s meaning from context or by lip-reading.

“My wife noticed it first,” Gaffney said. “I kept on saying, ‘Huh?’ ‘What?’ And I noticed at work, I would do lip-reading instead of looking people in the eye.

“I couldn’t hear water running in the sink. I couldn’t hear paper crinkling.”

Gaffney was showing the first perceptible signs of noise-induced hearing loss, an all too common problem in modern society that subtly and gradually destroys the ability to hear certain frequencies of sound.

While some experts believe that on-the-job noise-induced hearing loss such as Gaffney’s may be declining in the four years since new government regulations were instituted, others are concerned that hearing loss from recreational equipment such as stereos with headphones and motorcycles may be on the rise.

But perhaps the most regrettable aspect of both kinds of hearing loss is that they are preventable simply by protecting ears from loud noise, audiologists say.

“The people who are getting into trouble are the younger generation, who aren’t protecting themselves,” said Dr. Ronald Benz, president of the San Diego chapter of the Academy of Otolaryngology and Head and Neck Surgery.

“It’s such a gradual loss that you don’t notice it,” Gaffney said. “Like birds--I hadn’t heard birds in years.”

Though detailed statistics are not available, experts are certain that the largest segment of the estimated 24 million people with hearing losses are those whose ability to hear gradually declines with age. This natural phenomenon, known as presbycusis, will happen to one of every two people as they grow older.

Other causes of hearing loss include head trauma, infections, vascular problems and the ototoxic effects of medications such as aspirin. An additional 36 million Americans suffer from tinnitus, or ringing in the ears, according to Maurice Miller, professor of audiology at New York University.

But like Gaffney, others may be losing their hearing by exposing themselves to harmful levels of noise without realizing the damage they are doing.

“People don’t realize what they’re doing to their hearing, and to be careful when they’re around loud noises,” said Deborah Law, a clinical audiologist and president of Hearing Dynamics in Hillcrest.

Gene Czubernat, who was having his hearing tested at a free screening session in Mission Valley Saturday, said that his ability to discern speech from background noise has been damaged by exposure to artillery blasts during World War II and the constant pounding of heavy equipment on construction sites where he has worked without ear protection. “All the old-timers I know had hearing loss,” he said.

The screening is one of four Speech and Hearing Fairs being offered around the county this month by audiologists, physicians and speech pathologists. The final one will be at North County Fair, Saturday between 10 a.m. and 4 p.m.

Czubernat cannot hear speech directed at him from the back of his car, and has difficulty picking up conversation in a noisy room.

“If we’re at a dance, at a table, if you’re not next to me, I tune you out because I can’t hear you,” he said. He is planning to be fitted with hearing aids.

‘Personal Stereo’ Damage

Miller and Law, a continent apart, have both started seeing patients in recent years who have lost some of their hearing because of heavy use of “personal stereos,” those small, ubiquitous amplifier-and-headphones gizmos favored by joggers and beachgoers.

In tests of college students, researchers are also learning that an unexpectedly high percentage appear to have done enough damage to lead to later hearing loss, said Marc Kramer, an assistant professor of otolaryngology at New York Hospital-Cornell Medical Center in New York City.

The research “suggests that there’s a lot of noise-induced hearing loss that we didn’t know was there before,” Kramer said. “We’re talking about the general population. We’re talking about people of younger age having noise-induced hearing loss.”

Noise destroys hearing by damaging some of the approximately 40,000 sensitive sound-conductive hair cells in the inner ear. Once destroyed, they are replaced by scar tissue which does not conduct sound. The cells cannot be repaired surgically or treated with medication.

Typically, with noise-induced hearing loss, high-frequency sounds are the first to be lost. That is why Gaffney started being unable to detect certain consonants but could still understand vowels.

“Speech is across an entire pitch spectrum,” Law said. “And if you’re missing a part of it, you’re not going to understand it. So it’s a very frustrating experience.”

With further damage, hearing loss spreads into lower frequencies. Gaffney’s doctor told him that if he continued to work without ear protection, he would be deaf in three years.

Sensitivity to noise varies greatly from individual to individual. Volume and some length of exposure must be present together to cause damage. Thus, some experts say that short exposure to very loud noise--for example, walking past an operating jackhammer in the street--is not a major threat to hearing. (Benz, however, says that it is not a bad idea to cover one’s ears).

Prolonged Exposure

But prolonged exposure is hazardous. The federal Occupational Safety and Health Administration in 1983 set the threshold at eight hours of exposure to 85 decibels. That sound level or its equivalent is capable of causing significant hearing loss.

To demonstrate different volumes, Law measured common noise-producers around San Diego. A stationary band saw at a construction site registered at 85 decibels while idling and 97 decibels while in use. A jet flying 100 feet overhead registered at 110 decibels. A sand blaster registered at 96 decibels while idling and 107 decibels when operating. In contrast, a public library registered at 35 decibels.

There are various informal ways to determine whether noise is too loud. If you leave a noisy environment and your ears ring or feel muffled, “that noise is too loud,” Law said. The muffled feeling is actually temporary hearing loss, technically known as “temporary threshold shift.”

“TTS becomes a permanent shift at some unpredictable time for each individual,” Miller said. “It could be a week. It could be a month. But this much we know: Any noise capable of producing that temporary shift can in time produce permanent” damage.

Kramer suggested that any time you have to raise your voice to be heard at a distance of three feet, background noise is too high.

In 1981, OSHA estimated that 5.2 million workers were at risk for noise-induced hearing loss because of the noise levels in their work environments. It ordered most large employers using equipment over the 85 decibel level to institute hearing conservation programs that include providing ear protectors to employees and providing education on how and why to use the equipment.

Personal hearing protection is mostly a matter of common sense and awareness. Miller recommends keeping volume controls on personal stereos below 4 (although Kramer said that numbers on dials do not correlate to decibel levels). He also suggests wearing earplugs when doing such activities as snowmobiling, using a power mower or riding the subway. And, of course, frequent hearing tests should be taken.

Audiologists note that 90% of those with hearing losses can benefit from hearing aids, which have become much smaller and more sophisticated in the past 10 years. The devices, many of which can be inserted in the ear instead of placed behind it, now can be rigged to screen out background noises and enhance certain frequencies or dull others.

But primarily because of the stigma still attached to the devices, only about 25% of the people who could benefit from hearing aids wear them, said Jerry Johnson, president of the Hearing Industries Assn.

When Gaffney’s doctor first told him 10 years ago that he needed hearing aids, Gaffney got up and bolted from the office. “I expected the cane and the wheelchair to come next,” he said.

But after getting used to the idea, Gaffney was stunned by the improvement. “Even with just one hearing aid, I could hear birds, the crackling of paper, the running of water. Conversation became much more comprehensive and intelligible and I got much more out of it.” Gaffney has been wearing the aids for 10 years.

He also forces his firefighters to wear ear protection--even the young ones who insist they do not need it. “I’ve seen what (noise) has done to me,” he said. “And in my presence, anyway, I won’t let it happen to the other kids.”