Health Tips

Plugging in your earphones and listening to your favorite music may be the best way to dodge that boring conversation with your family members, but do you know that listening to extremely loud music for an extended period of time can actually damage your hearing?

Noise is a significant source of hearing loss, but you can protect your hearing. An important first step is to understand how noise causes hearing loss.

Sources of noise

Noise can be originated from various activities and environments, including your favourite Spotify playlist that you play from the smartphone if set at close-to-maximum volume. If you are repeatedly exposed to these sources of noise over time, they can cause hearing loss.

• Everyday activities, such as listening to music at a near-maximum volume, fitness classes, children’s toys.

• Events such as concerts, sporting events, motorized sporting events and movie theaters. (although these are impossible now given the COVID-19 pandemic)

• Tools such as power tools in a construction site, lawnmowers, sirens, firecrackers

Factors Affecting Hearing Loss

The extent of damage to your hearing caused by noise depends on:

Image credit: https://www.noisyplanet.nidcd.nih.gov/parents/too-loud-too-long#:~:text=Decibel%20Level%E2%80%8B&text=Sounds%20at%20or%20below%2070,greater%20risk%20for%20hearing%20loss.

Decibel levels

Sound is measured in its intensity, expressed as the unit decibels (dB). A whisper is about 30 dB, normal conversation is about 60 dB, and a motorcycle engine running is about 95 dB. Noise above 70 dB over a prolonged period of time may start to damage your hearing. Loud noise above 120 dB can cause immediate harm to your ears. Loud noises that are characterized by 120 dB and above are standing beside or near sirens and firecrackers.

Sounds May Be Louder Than What You Hear

How loud something sounds to you is not the same as the actual intensity of that sound. Sound intensity is the amount of sound energy in a closed space (measured in dB), whereas the loudness of sound refers to how you perceive the sounds. 

The dB scale is logarithmic, which means that loudness is not directly proportional to sound intensity. Instead, the intensity of a sound grows very fast. This means that a sound at 20 dB is 10 times more intense than a sound at 10 dB, not 2 times more intense as one may conventionally think. Also, the intensity of a sound at 100 dB is one billion times more powerful compared to a sound at 10 dB.

Likewise, two sounds that have similar intensity may not sound equally loud to you. A sound that seems loud in a quiet room might not be noticeable when you are on a street corner with heavy traffic, even though the sound intensity is the same.

The risk of damaging your hearing from noise increases with the sound intensity, not the loudness of the sound. It is important to discern such differences because it can affect how we estimate the noise level we expose ourselves to everyday. 

Signs of Hearing Loss

How to tell if you already have hearing loss? Here are some marked signs and symptoms:

1. Speech and other sounds seem muffled or covered up

2. Difficulty hearing high-pitched sounds (e.g., birds, doorbell, telephone, alarm clock)

3. Difficulty understanding conversations when you are in a noisy place, such as a restaurant

4. Difficulty understanding speech over the phone

5. Trouble distinguishing speech consonants (e.g., difficulty distinguishing the difference between s and f,  between p and t, or between sh and th in speech)

6. Feel the need to ask others to speak more slowly and clearly

7. Feel the need to ask someone to speak more loudly or repeat what they said

8. Turning up the volume of the television or radio

9. Ringing in the ears (known as tinnitus)

10. Experience extreme bothersome or pain when exposing to certain sound (hypersensitivity to certain sounds)

If you suspect you might experience hearing loss, kindly see a healthcare provider to get a hearing test.

The U.S Centers for Disease Control and Prevention (CDC) also recommends that all babies should be screened for hearing loss no later than 1 month of age. It is best if they are screened before leaving the hospital after birth.

Who is at a higher risk for loud noise-related hearing loss?

The following conditions and exposures can increase your risk for noise-induced hearing loss, in addition to long-term exposure to noises:

• Genetics and individual susceptibility to noise

• Long-term medical conditions, such as diabetes and high blood pressure

• Injuries to the ear

• Organic liquid chemicals, such as toluene

• Certain medicines, such as certain antibiotics (gentamicin), cancer treatment (cisplatin, carboplatin), and medications that contain salicylate (aspirin, quinine, loop diuretics). 

If you work in a noisy environment and/or belong to any of those above groups, you are encouraged to undergo regular hearing check-ups with your doctor to ensure your hearing ability is intact over time.

How Do I Know the Sound Level is Safe?

Here’s a rule of thumb:  If you need to raise your voice to be heard at an arm’s length, the noise level in the environment is likely above 85 dB in sound intensity and could damage your hearing over time.

Otherwise, you can also use a sound level meter (SLM) to measure noise around you. You can buy such measuring tools at any hardware store, or even download a SLM app for free on your smartphone (there are tons of them wherever you download your other apps!). 

The U.S. Environmental Protection Agency (EPA) and the World Health Organization (WHO) recommend maintaining environmental noises below 70 dBA over 24-hours (75 dBA over 8-hours) to prevent noise-induced hearing loss. 

Tips for Safe Listening

• Avoid noisy places whenever possible.

• Use earplugs, protective earmuffs, or noise-canceling headphones when around loud noises.

• Keep the volume down when using earbuds or headphones.

• Ask your doctor for a hearing checkup if you suspect you have had hearing loss.

References:

1. CDC - Loud Noise Can Cause Hearing Loss. https://www.cdc.gov/nceh/hearing_loss/default.html

2. NIDCD - Too Loud. Too Long. https://www.noisyplanet.nidcd.nih.gov/parents/too-loud-too-long#:~:text=Decibel%20Level%E2%80%8B&text=Sounds%20at%20or%20below%2070,greater%20risk%20for%20hearing%20loss.

3. Hearing Health Foundation - Decibel Levels. https://hearinghealthfoundation.org/decibel-levels

Written by

Ms Joyce Toh