Industry veteran and Jarvis Septic & Drain owner Gene Morris can attest to the dangers of noise exposure over time: “I’m 56, and my hearing above 2,000 hertz is gone. It’s just from not wearing hearing protection in my younger days.”

It’s a common trend among older operators and contractors. Despite regulations for hearing protection, this safety issue struggles for recognition and enforcement.

“We as young men think we’re Superman, and we’re never going to have those kinds of issues,” Morris says. “I do think the noise coming off the equipment, and even in general — the years and years and years of riding in the trucks — does take its toll on the hearing of the driver.

“Most of those older gentlemen who have experienced some hearing loss realize, ‘Oh, I better do something before it’s completely gone.’ I certainly think it’s something that needs to be addressed by the business owners to protect their employees because there is definite hearing loss associated with the industry.”

Industry regulations

Risk of damage to your hearing is a combination of how loud the sound is, how close you are to the source of the noise, and how long you’re exposed to that noise. “It isn’t a solid, continuous sound at a particular level. The measurement that they require is what they call a time-weighted average,” says Julie Steding, marketing manager for Sonetics.

Normal conversation is around 60 dB. OSHA guidelines require mitigation when sound reaches 90 dB over an eight-hour shift.

Though that seems like a small difference, “The decibel scale is logarithmic; it’s not linear. A 1 dB increase is a tenfold increase in the actual level of sound, so it scales up very quickly,” Steding says. “The difference between 60 and 90 is very noticeable. There’s no mistaking that there’s loud noise going on.”

At 100 dB, the allowable time frame for exposure is 2 hours. At 115 dB, OSHA guidelines show damage can occur after only 15 minutes of exposure or less.

“If you stand at the back of a vacuum truck and you open the valve and let the air free flow into the vacuum truck, you’re looking at the equivalent of a jet engine,” Morris says. “We’re in excess of 120 dB standing at the back of the truck.”

The burden is on business owners to provide mitigation when sound passes the OSHA threshold, meaning owners are also responsible for monitoring sound levels at their facilities and job sites. Fortunately, there are many ways to reduce noise for employees.

“What the regulation specifies is simply a noise level at which sound attenuation is required, or some sort of noise mitigation effort is required, and that’s one thing that I think people overlook sometimes; it doesn’t necessarily have to be exclusively or only hearing protection devices that you employ to try to mitigate the sound,” Steding says.

Sound mitigation falls into three categories: isolation, passive protection, and active protection.

Sound isolation

Noise mitigation efforts may begin by trying to isolate the source of the noise from the general population. “So you put loud equipment in a quiet room with extra sound insulation to protect the rest of the facility from the noise of that equipment,” Steding says.

This sound isolation can be an important factor when choosing equipment. Many manufacturers, such as Imperial Industries, consider sound level in their product design.

“On our vane pumps, we locate the oil catch muffler on the other side of the truck, and with the blower, typically we locate the silencer on the opposite side of the truck as well. That helps bring down the noise,” says Kyle Haase, Imperial Industries commercial sales manager.

Remote-controlled rigs are another option, allowing operators plenty of distance from the equipment.

“Remote is the big push on our end,” Haase says. “You’re not directly in front of the pump when you’re operating. Usually you’re at the actual lid or the hole, and that’s where you’re doing all of your operations with the wireless remote, so the end user is not standing directly in front of the pump.”

If a particular manufacturer doesn’t have sound-mitigating options, there are ways for contractors to limit noise on their own.

“I have found that some of the camlock fittings we use on our hoses produce a different decibel of sound,” Morris says. “I stumbled on it by accident, and I’ve actually switched all my hose couplings.”

The configuration of the coupling makes a difference on the airflow, changing the pitch. Morris also recently changed his vacuum truck over from a vane pump to a blower, which he thinks is quieter — but it may not be as simple as one being quieter than the other.

“A lot of our units use the National Vacuum Equipment blowers, and they’re fully enclosed in a cabinet that is all insulated as well, so that helps reduce the noise,” Haase says.

Passive vs. active

Even when doing everything possible on the equipment side, it’s still heavy machinery. At a certain point, the focus needs to shift onto operators, and the simplest solution comes down to earplugs and earmuffs, which OSHA defines as passive protection.

“Passive noise attenuation is a reduction in the sound pressure level that reaches your eardrums,” Steding says. “So earplugs and earmuffs tend to be passive noise attenuation, meaning they work by virtue of covering up your ears, or plugging up your ear canal. They are not employing any kind of active strategy.”

There are different levels of protection even within this basic category.

“Depending on the manufacturer and the style, they have differing amounts of noise attenuation, or sound reduction that goes on,” Steding says, but contractors need to use them properly. “I emphasize wearing them properly because there’s a way to wear them improperly that will reduce their effectiveness. You don’t want to just hand someone a hearing protector without any kind of instruction.”

Going one step further, an active attempt for hearing safety would be some sort of technology in the hearing protector that further reduces the amount of noise a contractor is exposed to. This kind of upgrade provides added safety and communication efficiency on top of noise attenuation.

For example, Sonetics’ wireless communication headsets provide 20 dB of passive protection, also incorporating “listen-through technology.” It is an adjustable noise control technology that lets in certain amounts of outside sound to balance protection and awareness on any particular job site.

Keep your hearing

In industries saturated with rules and regulations — like excavation and construction — it can be easy to overlook something as seemingly innocuous as hearing safety. Contractors who have been around long enough can tell you it’s worth keeping in mind — and not just for the benefit of employees.

“Hearing protection should be provided. It should be mandatory that it be worn,” Morris says. “Even though it’s not popular, if the employee is not using the hearing protection, the business owner should write them up, in order to protect themselves from a possible OSHA violation.”

As the invisible threat, its effects can take a long time to manifest, as Morris and many contractors like him are lamenting in their later years.

“It’s something that young men need to realize — that you can lose your hearing around this type of work,” Morris says. “Like I said, in our younger days we think we’re Superman and we’re invincible. Reality catches up with you, but by the time it does, it’s too late.”