News & Blogs
August 13 2019

Are You Going Deaf? Everything About Noise-Induced Hearing Loss


People don’t often think about their ears or sense of hearing that much. Understandably, if you don’t feel that there’s something wrong with it, you wouldn’t bother seeing an Otorhinolaryngologist (an Ear, Nose, Throat doctor). But often, this negligence goes overboard that you don’t even pay attention to how much sound your ears can tolerate.

Prolonged and frequent exposure to loud sounds can take a toll on your sense of hearing. When your ears start to weaken, and you start to experience hearing problems, it’s only a matter of time before you completely lose it.

What is Noise-Induced Hearing Loss?
Noise-induced hearing loss (NIHL) is the loss of hearing due to damage of the tiny hair cells in the ears, which send the sounds to the brain. Loud noises and sounds produce powerful vibrations in these hair cells that can permanently damage them. NIHL can be immediate or can also take a long time to manifest; it can also be temporary or permanent and affect one or both ears.
Unfortunately, hair cells are not replaceable—once the damage is done, you are sure to feel the effects. Even if you don’t notice the loss today, you could have problems with it in the future. This makes NIHL one of the most common sensorineural hearing deficit, second only to presbycusis or age-related hearing loss.

What Causes Noise-Induced Hearing Loss?
As mentioned, loud noises and sounds are the usual cause of NIHL. Even a short exposure to excessive volumes of sound—for instance, a gunshot within a close range—is already enough to do some harm. Naturally, the damage can be more significant if contact is too frequent or long-lasting.

But how loud is loud? Any sound above 85 decibels (dBA; the measure of the intensity of a sound or degree of loudness) can lead to NIHL, though the rate of recurrence and length of time are important factors to consider. The louder the noise, the sooner NIHL can happen.

For reference, here are the dBA levels of the sounds you hear every day:
●      Typical conversation: 60–70 dBA
●      Movie theater: 74–104 dBA
●      Motorcycles:  80–110 dBA
●      Sporting events, concerts, and music through earphones at max volume: 94–110 dBA
●      Sirens: 110–129 dBA
●      Fireworks: 140–160 dBA

Based on the list, most of the loudest noises come from recreational activities. However, even workplace and household-related activities produce damaging levels of sound. Lawnmowers, leaf blowers, and woodworking tools can produce somewhere between 90 to 110 dBA.

Meanwhile, those working in agriculture, construction, mining, and military are also exposed to tools, machinery, and weapons that emit loud noises daily. In this case, employers have the responsibility to provide them with the right ear protection. Other steps include regularly maintaining machinery, isolating the noise, and developing a hearing conservation program for the employees.

How is Noise-Induced Hearing Loss Developed?

Hair cells in the ears—to be specific, on top of the basilar membrane of the cochlea—are responsible for sending sound signals to the brain, but they must first exert a shearing force on the stereocilia or microscopic hair-like projections perched on top of the hair cells.

The stereocilia bump against an overlying structure and bend so that pore-like channels on its tips open up and obtain the chemicals into the cell to create an electrical signal, which is then carried to the brain. However, excessive force to the stereocilia causes cellular metabolic overload and leads to cell damage and death.

NIHL, therefore, can also be referred to as the excessive wear-and-tear of the delicate inner ear structures. Discontinuing your exposure to damaging noise levels can cease the progression of hearing loss, though the damage can’t be undone. Experiments on animals suggest that free oxygen radicals may resolve the noise damage to hair cells.

Should You Be Alarmed?
If you believe that you’ve been exposed to excessive noise, you can get yourself screened. During the screening, your entire medical history is considered, and physical examination and audiometry are performed. If results show evidence of hearing loss, a referral for full audiological evaluation is recommended. Here are some symptoms that may indicate the need to be tested:
●      The sounds, voices, or noises you hear are muffled, and you don’t understand what people are saying
●      Pain in the ears and tinnitus (ringing, whooshing, roaring, or buzzing sounds) following exposure to loud noise
●      You start talking loudly or shouting

Noise-Induced Hearing Loss is Preventable
NIHL is the only hearing problem that can be prevented. Understanding the hazards of excessive noise and sound is the first step in keeping your sense of hearing healthy. Here are other steps you can take:
●      Know the possible sources of damaging noises and sounds
●      Adopt habits to protect your ears
○      Avoid or limit exposure to loud sounds and noises
○      Turn down the volume to safe levels if possible
○      Move away from the source
○      Use hearing protection devices like earplugs if the noise can’t be avoided
●      Protect the ears of children
●      Share information with your family and friends
●      Replacing machine parts that are maybe causing loud noises or use a lubricant to reduce friction

Protecting your hearing for as long as you live is necessary since the damage to your ears is permanent and NIHL is irreversible. Regularly going for check-ups will help ensure that your ears are in tip-top shape.

If you believe that you are at risk for NIHL and are concern about potential hearing loss, seek a hearing evaluation today.