Construction Hearing Loss: Searching for Sound Solutions
When considering construction worker injuries many people think of examples of injuries caused by physical accidents from impacts such as a fall from a ladder or scaffolding. However, there are many other types of injuries that occur in addition to those that occur from strictly physical accidents. In fact, one of the most common injuries suffered by construction workers is hearing loss.
Construction workers are often exposed to loud noises which make them especially susceptible to the loss of hearing. According to Audicus, there are around 30 million workers in the U.S. who are exposed to hazardous noise on the job.
Hazardous noise is defined as noise which exceeds 90bD (decibels) for an extended period of time. There is a 60 percent chance of construction workers losing their hearing if they are exposed to hazardous noise throughout their career.
Compared to a 9 percent risk factor for no noise exposure, and a 30 percent risk in manufacturing, construction, along with mining, remain the top two high-risk professions in industry.
The Main Causes of Hearing Loss on a Job Site
The most common cause of hearing loss on a job site is intuitive: a lack of use of protective hearing equipment, which is required by law. There may be one of two common reasons why construction workers do not use hearing equipment.
First, the employer may not make them aware of the risks of working in an environment with hazardous noise and may not provide them with appropriate hearing protection. Secondly, the worker may choose not to wear protective hearing equipment.
A third, often overlooked, reason is that existing hearing protection may be insufficient. When hearing protection does not prevent hazardous noise from reaching the ear, or fails to do so effectively, the worker may be unknowingly exposed to excessive noise.
Lack of equipment to control noise can be a contributing factor to hearing loss as can failing to take breaks when working in an area containing hazardous noise. Finally, a lack of training about how to wear hearing protection can contribute to the risk of overexposure and hearing loss.
Where Hearing Loss Occurs
Hearing loss typically occurs in areas where noise levels exceed 90bD – the established noise level that is deemed “hazardous” to workers’ hearing. Job sites where workers are exposed to, or must use or interact with, heavy machinery, jackhammers, sledgehammers, nail and bolt drivers, electrical saws, and constant noise from demolition pose the most serious risk.
When Hearing Loss Occurs
Hearing loss usually does not occur upon a single overexposure, although if the noise is loud enough, it may permanently or temporarily cause hearing loss. Permanent hearing loss occurs over time when repeated overexposure is experienced by the worker. Workers who reach the age of 50, and have been working in construction for at least several years prior, are the most likely to experience hearing loss.
Workers who start young, and enjoy a lifetime of work in construction, may be at an increased risk for hearing loss, particularly if their exposure levels exceeded the maximum threshold during most workdays.
How Hearing Loss Occurs
Hearing loss happens in one of two ways.
Conductive Hearing Loss:
- Sound energy is blocked before it can reach the inner ear. This typically occurs because of an obstruction like earwax or a tumor is blocking sound from getting to the ear. This is typically not associated with damage caused by overexposure to noise or sound on a construction site, but it must be ruled out by a physician.
Sensorineural Hearing Loss:
- Sensorineural hearing loss is a type of hearing loss which occurs because of some type of damage to the ear. Damage may occur to the inner ear or the nerves that are responsible for hearing (auditory nerves). Damage can also occur to the tympanic membrane (ear drum) which will prevent hearing.
With repeated overexposure to hazardous noise, construction workers are most likely to be exposed to sensorineural hearing loss at some point during their lives. Hearing does not immediate disappear. Rather, as damage accumulates, hearing gradually fades away.
Over time, the individual may notice this manifesting as various symptoms. Symptoms of hearing loss include:
- Muffled or distorted hearing;
- Difficulty hearing high-pitched noises, like birds singing;
- Difficulty hearing soft noises like crickets chirping;
- Difficulty hearing alarm clocks, watch alarms, telephones, or doorbells;
- Difficulty understanding telephone conversations while in public or where background noise is present; and,
- Ringing in the ear, also called tinnitus, after overexposure;
Hearing loss can be mild, moderate, or severe. Mild hearing loss is usually associated with the inability to hear soft sounds or difficulty understanding speech in noisy environments. Moderate hearing loss occurs when workers are unable to hear soft and moderately loud sounds and have considerable difficulty understanding speech, especially background noises.
Severe hearing loss occurs when some loud sounds are inaudible and communication is impossible or extremely difficult without a hearing aid.
Prevention and Treatment
Prevention is the best treatment. Loud noises are dangerous to human ears, and the impact they can have can be devastating. Noise levels of just 100dB for 15 minutes are enough to cause damage to the inner ear. 100dB is the “loudness” of a typical MP3 player at full volume.
Working in environments where construction is going on represent an inherent danger, because the noise level often exceeds the 100dB level. Once destroyed, the microscopic hair cells of the inner ear don’t grow back. They also cannot be artificially recreated by any known medical means. Once destroyed or damaged, permanent hearing loss occurs.
Tinnitus is just one symptom that results from the damage and destruction of those hair cells.
In addition to hearing loss, workers may experience nervousness, a reduced ability to concentrate, a reduction in the quality of sleep, an inability to get to sleep in a timely or efficient manner, reduced productivity, and an increased risk of work-related accidents.
Workers who lose their hearing are also more susceptible to feeling isolated and may have trouble communicating with co-workers.
For these reasons, workers should always wear specially-designed ear protection that is rated for the construction job and site they are working on. Hearing protection comes in two versions: passive and active.
Passive protective devices or uniform-attenuating protectors use mechanical blocks or means to filter sounds to provide equal attenuation across the audible frequency range. Attenuation refers to the general reduction in strength of a signal. In the context of noise, it means the reduction of noise or sound. Attenuation is expressed in dB.
The sounds heard with passive protection in place are more natural, clearer and less distorted than protection provided by low-quality alternative or conventional hearing protectors. Workers who are continually exposed to loud noises benefit the most from this type of hearing protection. When communication is secondary to work, this type of hearing protection may be ideal.
For passive hearing devices to work, however, they must be properly fitted and used. As workers get hearing protection without distortion or muffling, they feel less isolated on the job site. If possible, the hearing protection device should be custom-fitted for the individual, and considerable time should be spent explaining the importance of always wearing hearing protection.
Some workers may have the tendency to only wear hearing protection when they are currently working, but may not wear the protection when they have finished the job but are still on the construction site in an area where hazardous noise exists. Workers must wear their passive hearing protection until they are clear of hazardous noise areas.
Active hearing protection or “level dependent” hearing protectors block sound and also use electronic means to transmit low-level sounds through the hearing protector.
The electric signal amplifies incoming sounds up to a specific level. Anything that exceeds that level is automatically reduced, thus preserving the wearer’s hearing through limiting and preventing overexposure.
These devices also employ amplifiers for background noise. Rather than providing equal attenuation, they provide it selectively. Loud noises, even sudden loud noises, are reduced to comfortable levels, while low dB noises are not muted or attenuated. The result is that the worker can carry on a conversation with another co-worker without the need for special communication equipment and without removing the protective gear, risking overexposure.
Electronic devices also allow users control over the attenuation of hazardous noise, essentially allowing customization of hearing. These provide the best hearing protection in environments where hazardous noise occurs, but where communication is still important, even critical.
Another benefit of these devices is that special FM or infrared (wireless) capabilities can be integrated into the device to provide one or two-way communication. This allows workers to communicate with each other without risking overexposure to hazardous noise levels in situations where they are spaced apart and cannot effectively communicate by other means.
Again, for these devices to work, they must be properly fitted and worn during times when hazardous noise threatens the individual. Like the passive device, it should be custom-fitted and tested prior to use. Because it’s electronic, it should be inspected prior to each use to make sure that the power is on, or that the device is properly charged and functioning normally.
Periodic replacement and maintenance is necessary with these types of ear protectors, which makes them a more expensive option.
Hearing Aids, Implants and Resources
Once hearing loss occurs, options for treatment are limited. There is no official cure for hearing loss, but there are some treatments which may improve hearing or augment it. While cochlear implants are an available technology, they are still relatively expensive and full hearing restoration is not guaranteed. A second option is a hearing aid, which does not restore lost hearing, but rather amplifies sound, making hearing easier.
Getting A Cochlear Implant
Cochlear implants have been approved by the Food and Drug Administration for children and adults who are deaf or severely hard-of-hearing. As of December 2012, there have been roughly 324,000 individuals worldwide who have had the procedure and received implants.
In the U.S., only 58,000 implants have been done. Some adults who have lost their hearing completely may be candidates for implants. For these individuals, they must relearn how to hear after the procedure and full hearing restoration is never guaranteed. Patients must learn to associate the signal provided by an implant with sounds they remember.
Health insurance may cover the procedure, but not always.
The implant itself consists of a microphone, which is capable of picking up sounds from the environment. A speech processor arranges sounds that are captured by the mic. A transmitter receives signals from the speech processor and then converts them into electrical impulses. Finally, an electrode array collects and transmits the impulses from the stimulator to various regions of the auditory nerve.
The implant will not restore normal hearing. Instead, it gives deaf or hard-of-hearing individuals useful representations of sounds in the environment. It can also help the individual better understand speech.
A hearing aid is a device that is fitted into the ear which effectively amplifies sound. Hearing aides are commonly used by older adults or individuals who are hard-of-hearing. They do not replace the human ear, and are not a replacement for cochlear implants.
Instead, they capture the sounds of the environment and convert them into electrical signals. The hearing aid amplifier increases the strength of the signal. Then, the aid converts the signal back into sound and sends it into the inner ear.
The brain hears and understands the sound just as it would unaided. The technology requires that the patients still have basic functional hearing and that the ear drum assembly, inner, middle, and outer ear are structurally intact. The labyrinth system of the ear must also be normal or at least not so abnormal that hearing becomes physically impossible.
What Should You Do If Your Hearing Is Already Affected?
If you feel that the risks that you’re being asked to take are unreasonable, you’ve suffered hearing damage on the job, or if you’ve been injured in some other way on a construction site, don’t hesitate to speak with an attorney. You have rights, and you shouldn’t be afraid to assert them.