Large tractor mowing a field

Hear that? Maybe not, if you have been around farm tractors and other agriculture machinery your entire life.

According to the United States Department of Labor, twenty-two million workers are exposed to potentially damaging noise at work each year. Many of these worker are farmers and ranchers.

Exposure to tractors, forage harvesters, chainsaws, combines, grain dryers, even squealing pigs and guns, can lead to significant hearing loss, says Dr. Richard Kopke, M.D., FACS, chief executive officer of the Hough Ear Institute in Oklahoma City. Kopke was in the military of 26 years and has conducted research on noise induced hearing loss since 1996.

“Maybe 30 to 40 percent of my patients are farmers,” Kopke said. “Noise damage to the ear is almost epidemic.”

“Most of the patients I see are in three main areas of occupation: the military, oil patch or farmers,” Kopke said.

The focus on hearing loss is especially important for family farmers with young children.

“The noise exposure of young people growing up on the farm stays with them even after the leave the farm for another career,” Kopke said.

The Oklahoma doctor is known worldwide for his work in the field of noise-induced hearing loss. He refers to the dilemma as the “silent hurt.”

When you damage your ears with noise, you often realize it because it’s not always painful,” Kopke said. “It’s not the shotgun blast fro last weekend’s hunting trip as much as it is the everyday, constant exposure to machinery. IT gradually sneaks up on you. You may not know until it’s too late.”

The most practical way to protect from hearing loss is with personal hearing protection, such as ear plugs in the ear canal or ear muffs. One of the leading manufacturers of hearing protection is Etymotic Research, Inc.

“Etymotic is one of the top companies in the country for protecting hearing,” Kopke said.

Dr. Wayne Staab, Ph.D. Dammeron Valley, UT, is an internationally recognized authority in hearing aids and consults on issues related to hearing protection. Staab has conducted research specific to agriculture.

Both Staab and Kopke agree hearing loss cannot be reversed today.

Damage is a function of the loudness of the noise and the duration or frequency of the noise.

Kopke says the damage can be life altering.

“Hearing loss can cause one to be socially isolated leading to depression,” Kopke said. He added other health areas such as loss of balance due to hearing damage, can impact one’s life.

Kopke said high quality foam ear plugs work well in most circumstances, but you must get them deep into the ear canal.

What exactly is too much noise?

Most of us probably think attending a rock concert or running a chain saw all day is the type of noise-induced hearing damage doctors are talking about. In actuality, it is much more diverse.

“Anything you have to raise your voice above the the sound of what you’re using, it’s probably a damaging noise,” Kopke said. “If the ringing lasts for more than 15 minutes, you’ve probably done some damage,” Kopke said.

Have you noticed ringing in the ears after shooting off fireworks or hitting a hammer on metal? The Oklahoma City doctor offers some guidelines on when to know if your hearing has been damaged.

Sound is measured in decibels (dB). Here is a quick reference to measure sound in everyday situations:

It is important to knwo that 85 to 90 dB is a relatively safe zone, 85 is about waht you would experience in a modern, insulated tractor cab. The human voice is 60. Road traffic is about 80. Chopping silage is 90. Squealing sows is about 100. CHainsaw is about 115. Shotgun blast is 120.

It’s not just the sound level that contributes to hearing damage, but it’s also the duration of the exposure.

According to Patty Johnson, AuD, Director of Audiology at Etymotic Research, Inc., the National Institute for Occupational Safety (NIOSH), has established Recommended Exposure Limits (RELs) for noise, based on the best available science and practice.

“The REL for noise is 85 dB as an 8 hour, time weighted average; exposures at or above this level are considered hazardous to hearing,” Johnson said. “This standard uses a 3-dB exchange rate: for every 3-dB increase in noise level, the recommended exposure limit is halved. This means that 85 dB is allowed for 8 hours; 88 dB is allowed for 4 hours, 91 dB is allowed for 2 hours, 94 dB for one hour, and so on. This is why it’s important to consider not only the sound level, but also the duration of the exposure. If a modern insulated tractor cab has a typical sound level of 85 dB, short exposures don’t pose much of a hazard. However, during harvest, a farmer may be in that cab far longer for 8 hours, so in that case, the 85-dB exposure presents a risk to hearing because of the length of the exposure time. The simplest solution to protecting hearing is to use hearing protection any time an exposure is 85 dB or greater, since exposures are cumulative over our lifetime. If a sound is loud enough that you have to raise your voice to be heard at a distance of three feet, it’s loud enough that you should be using hearing protection.”

Is there a miracle cure for hearing loss?

The best thing is to protect the ears, but within five years we could have something to reverse the loss.

Kopke said recent research indicates the nerve endings on the inner hair cell in the cochlea are much more sensitive than the hair cells themselves. If those nerve endings can be repaired, perhaps hearing loss can be restored.

“One drug that we’re working on is a pill that may regrow the nerve endings between the hearing nerve and the inner hair cells,” Kopke said. “This could restore some hearing and reduce the ringing sound. The second approach involved regenerating sensory cells in the inner ear. We have another treatment that would be injected through the ear drum that would regenerate these cells.”

These “hairs” are more like glass rods than the wispy hairs we have on our heads. These cells are very deep inside the inner ear.

Kopke emphasizes they are still in the research stage so his best advice today is to wear hearing protection.

This article was originally featured in the Fall 2017 edition of America’s Farmers & Ranchers and has been shared with permission by the author, Sam Knipp.