Noise-Induced Hearing Loss

Summary

Dr. Ted Vena discusses Noise Induced Hearing Loss (NIHL), the second most common cause of hearing loss globally. Unlike age-related hearing loss, NIHL is preventable. He explains how exposure to loud noises, like jackhammers or concerts, can cause permanent damage to the ear's hair cells. Vena highlights the importance of recognizing the distinct pattern of NIHL on audiograms, showing how high-frequency hearing is most affected. He emphasizes the importance of protecting your ears from harmful noise levels to prevent permanent hearing loss and tinnitus, a common side effect.

Takeaways

• 😀 Noise-induced hearing loss (NIHL) is the second most common cause of hearing loss globally, following age-related hearing loss (presbycusis).
• 😀 While aging cannot be prevented, noise-induced hearing loss is entirely preventable with proper precautions.
• 😀 The ear is vulnerable to noise damage, similar to how staring at the sun can damage the eyes.
• 😀 People in areas with less industrial noise, like elderly individuals in Africa, tend to have better hearing than those in industrialized countries.
• 😀 The ear was designed for soft sounds and speech, not for high decibel levels from industrial noise or headphones.
• 😀 The rule for noise-induced hearing loss is exposure to sounds over 85 dB for prolonged periods, with the risk increasing as sound levels rise.
• 😀 Prolonged exposure to noise at 85 dB for 8 hours or more can lead to permanent hearing loss. The risk increases with higher decibel levels.
• 😀 Tinnitus, a ringing or buzzing sound in the ears, is a common side effect of noise-induced hearing loss and is caused by damage to the hair cells in the cochlea.
• 😀 Tinnitus may subside temporarily after exposure to loud sounds, but repeated noise exposure can cause permanent damage to hair cells in the inner ear.
• 😀 A hearing test (audiogram) shows noise-induced hearing loss by revealing difficulty hearing high-frequency sounds while still hearing low and mid-range frequencies normally.

Q & A

What is noise-induced hearing loss (NIHL)?

Noise-induced hearing loss (NIHL) is a form of hearing impairment caused by prolonged exposure to loud noises. It is the second most common cause of hearing loss in the world, after presbycusis (age-related hearing loss).

What is the main difference between noise-induced hearing loss and presbycusis?

Presbycusis is hearing loss due to aging, a natural process that affects most people as they get older. In contrast, noise-induced hearing loss is preventable and is caused by exposure to loud sounds.

Why do elderly people in Africa tend to have better hearing than elderly people in North America?

Elderly people in Africa generally experience less industrial noise pollution, which may contribute to better hearing. The noise levels in industrialized countries like North America are much higher, leading to a higher risk of noise-induced hearing loss.

What is the threshold decibel level that can cause noise-induced hearing loss?

Exposure to sounds at or above 85 decibels (dB) for extended periods (like 8 hours) can lead to noise-induced hearing loss. As the decibel level increases, the safe exposure time decreases.

How does the duration of exposure to noise relate to the risk of hearing loss?

The risk of noise-induced hearing loss increases with both the loudness of the sound and the duration of exposure. For instance, exposure to 90 dB for 8 hours is hazardous, but if the noise level rises to 95 dB, the safe exposure time is reduced to just 2 hours.

What is tinnitus and how is it related to noise-induced hearing loss?

Tinnitus is the perception of sound (such as ringing or buzzing) when no external sound is present. It is a common side effect of noise-induced hearing loss, caused by damage to the hair cells in the ear that are responsible for detecting sound.

Why do some people experience tinnitus after attending a loud concert?

After exposure to loud music, such as at a concert, the hair cells in the inner ear can be temporarily damaged. This often leads to the ringing or buzzing sound known as tinnitus, which may disappear after a short time if no further damage occurs.

How does noise-induced hearing loss appear on an audiogram?

Noise-induced hearing loss has a distinct pattern on an audiogram, where the person hears well in the lower and mid-range frequencies but struggles with higher frequencies. This is because noise exposure primarily affects the ability to hear high-frequency sounds.

What role does the shape of the ear play in hearing, and how does it affect noise-induced hearing loss?

The shape of the ear helps amplify high-frequency sounds, which is particularly important for understanding speech. However, with noise-induced hearing loss, this natural amplification works against the individual, as high frequencies are the first to be damaged.

What can be done to prevent noise-induced hearing loss?

Noise-induced hearing loss is preventable by using hearing protection, such as earplugs or earmuffs, in noisy environments, limiting exposure to loud sounds, and maintaining safe listening practices when using headphones or attending concerts.