October is National Protect Your Hearing Month

According to the Centers for Disease Control and Prevention, 22 million workers face dangerous levels of noise exposure on the job each year, and millions more report never or rarely wearing hearing protection at entertainment venues or loud sporting events. Once a person experiences hearing loss from loud noises, the damage can be irreversible. It is important to take precautions to protect your hearing before it is too late.

How Does Hearing Loss Happen?

Hearing loss occurs when there is a problem with the ear, the nerves connected to the ear, or the part of the brain that controls a person’s ability to hear. When a person sustains short-term or permanent hearing loss, the following factors are usually at play:

• Damaged hair cells in the ear. On average, a person is born with 16,000 hair cells in their cochlea (inner ear). Hearing tests generally cannot detect an issue until 30-50  percent of a person’s hair cells have been damaged or destroyed from hazardous levels of noise exposure.
• Damage to the nerves in the ears. Similar to how noise can damage or destroy the hairs in the cochlea, it can also damage the auditory nerve that carries signals from the ear to the brain.
• Damage to the cells and membranes in the cochlea, which typically results from a single loud noise or repeated exposure to high noise levels.

The Mayo Clinic reports that the most common signs and symptoms of hearing loss includes difficulty understanding words, especially against background noise or in a crowd; muffling of speech or other sounds; trouble hearing consonants; turning up the volume on televisions or radios; frequently asking others to speak more slowly, clearly, or loudly; withdrawal from conversations, and avoidance of social settings. 

If you are experiencing trouble hearing, schedule an appointment with your healthcare provider.

Preventing Hearing Loss at Work

While almost all cases of hearing loss that result from high levels of occupational noise exposure are preventable, each year millions of people – like those without proper training, supervision, and personal protective equipment – sustain irreversible hearing damage.

To reduce noise-related hazards, the Occupational Safety and Health Administration (OSHA) requires that employers take steps to protect workers. Here are a few examples of OSHA’s safety standards:

• Maintain and lubricate machinery and equipment to avoid excessive noise during start up and operation.
• Choose low-noise tools and machinery.
• Enclose or isolate noise sources. Place a barrier between the noise source and employee, like curtains or sound walls.
• Provide workers with a quiet area so they can gain relief from hazardous noise sources.
• Operate especially noisy machinery when fewer people are in close proximity.
• Limit the of time that workers spend around known noise sources.

Monthly Toolbox Talk

For most people, hearing loss cannot be restored. Exposure to constant loud noises on a construction site can lead to hearing problems if certain precautions are not taken. 

Exposure to normal noise levels does not cause hearing loss: hearing loss occurs as a result of overexposure to high noise levels. Noise is measured in "decibels” (dB); the higher the decibel, the louder the noise. Here are a examples of various noise levels:

• 20dB: Soft whisper
• 30dB: Leaves rustling, very soft music
• 60dB: Normal speech
• 85dB: Heavy machinery with soundproof cab
• 90dB: Lawnmower, shop tools
• 100dB: Heavy machinery without soundproof cab, motorcycles
• 115dB: Loud music, sand blasting
• 140dB: Jet engine, shotgun

Hearing protection must be used for anyone who is generally exposed to 90 dB or more over the course of their workday. Sounds above 120 dB can cause hearing damage after brief exposure and should be avoided unless hearing protection is worn.

Most hearing protection is given a Noise Reduction Rating (NRR) of 20-30dB. However, it’s recommended to deduct 7dB from an earplug’s NRR to better determine the protection provided. For example, if a jackhammer’s noise exposure level is 102dB and we use earplugs with a NRR of 29, the actual NRR is 22dB. This reduces the noise exposure from102dB to 80dB, which is below the OSHA permissible exposure limit.

Not every type of hearing protection is good for every type of noise. Disposable foam earplugs are fine for some types of noise exposure; earmuff-type protection is suitable for another.

Source: Occupational Safety Consultants, www.WorkRiskFree.com