Hearing Loss 101
Table of Contents
Understanding Hearing
Our ears, vital for sensing sound, have three parts: the outer, middle, and inner ear.
Outer Ear:
- The outer ear has 3 components: the pinna, ear canal, and eardrum.
- The pinna captures sound waves, which travel through the ear canal, striking the eardrum. The eardrum then begins to vibrate and passes the sound onto the middle ear.
Middle Ear:
- The middle ear is the air-filled space behind the eardrum. It contains the 3 smallest bones of the human body, called ossicles.
- The ossicles transmit vibrations from the eardrum to the cochlea (inner ear).
Inner Ear:
- The inner ear contains the organ of hearing, the cochlea, and the organ of balance, semi-circular canals.
- Ossicles from the middle ear link to the cochlea, causing vibrations in the cochlea’s fluid.
- The auditory nerve, connected to the cochlea, detects the vibration and sends sound information to the auditory cortex in the brain.
Understanding Hearing Loss
What is Hearing Loss?
Hearing loss means you have a decreased sensitivity to sounds that one normally hears. You can’t reverse hearing loss. However, you and your doctor or hearing healthcare provider can take steps to improve what you hear.
Hearing loss is often called an invisible condition. Because others can’t see that an individual has hearing loss, it can be easily overlooked. Raising awareness about its hidden impact is crucial for promoting accessibility and understanding for the hearing loss community.
Hearing loss is more than just an inconvenience. Even mild hearing loss can have serious social, health and economic consequences. More information on the impact of hearing loss on Canadians can be found here.
How Common is Hearing Loss?
Hearing loss is one of the fastest-growing health crises in Canada. Published in 2016, the Canadian Health Measures Survey (CHMS) found that 19% of Canadians experience a significant hearing loss that interferes with their ability to hear speech. 4.3% of Canadian children (aged 6-19) have some degree of hearing loss. Rates of hearing loss continue to climb across all populations, but young people (12-35) are especially at risk due to their increased exposure to loud environments.
Types, Causes and Treatment of Hearing Loss
Hearing loss is most commonly caused by aging and prolonged loud noise exposure. Other causes of hearing loss include accidents, illnesses, certain drugs/chemicals, and genetics.
There are three types of hearing loss: Conductive, Sensorineural and Mixed (which is a combination of conductive and sensorineural hearing loss).
Conductive hearing loss results from issues in the outer or middle ear, hindering the full transmission of sound to the inner ear. Common causes include ear infections, perforated eardrums, wax build-up, or damage to the tiny middle ear bones, affecting 10% of adults with hearing loss.
Sensorineural hearing loss results from damage to the inner ear, including the cochlea’s hair cells or auditory nerve fibers. Common causes are age and exposure to loud noise, leading to ‘wear and tear’ over time. Approximately 90% of adults with hearing loss experience sensorineural issues, often treatable with hearing aids, while severe cases may consider cochlear implants.
Mixed hearing loss happens when someone has both conductive and sensorineural hearing issues. For instance, a 68-year-old who worked in a noisy factory might have sensorineural hearing loss and an ear infection (conductive hearing loss). The conductive part can often be medically treated, while hearing aids are used for the sensorineural part.
How Do I Know If I Have Hearing Loss?
Hearing loss is complex. We all hear differently and as such, we may have different degrees of hearing loss and how we actually hear can also be different.
Signs of hearing loss can be subtle and surface slowly, or early signs of hearing loss can be significant and come on suddenly. Either way, there are common indications and hearing-impaired signs.
You might have hearing loss if you:
- Have trouble hearing clearly, especially when there is background noise
- Find group conversations are difficult to follow
- Play the volume on the TV or radio too loudly
- Think everybody is mumbling or that sounds are muffled
- Frequently ask people to repeat themselves
- Have trouble hearing when a speaker isn’t facing you
- Find telephone conversations are becoming more difficult
- Avoid social situations because you aren’t confident in your hearing
What Do I Do If I Suspect Hearing Loss?
Get your hearing tested by a qualified practitioner, either at a private clinic or a hospital (with a doctor’s referral for hospital testing). Some private clinics charge for tests, while others offer them as complimentary. During the appointment, you’ll answer medical questions, discuss your hearing difficulties, and receive recommendations, possibly for hearing aids if needed. If medical investigation is necessary, a referral to a doctor or ENT specialist will be made.
When purchasing hearing aids, consider the location and staff’s suitability for a long-term relationship. Multiple appointments, including annual visits, are typical. Understand the full cost coverage of hearing aids. Health care processes vary by province or territory, so find out about the cost responsibility for tests and aids before your clinic visit.
Hearing Loss Prevention
Noise-Induced Hearing Loss
While some hearing loss is inherited, others like Noise-Induced Hearing Loss (NIHL) can be prevented. NIHL results from prolonged exposure to loud sounds, potentially causing permanent damage. We used to believe that NIHL was mostly caused by workplace exposure, recent studies indicate that teenagers and young adults may suffer permanent hearing loss due to everyday noisy activities like listening to loud music or playing loud video games with headphones.
How Loud is Too Loud?
Scientists measure the levels of different sounds with a unit called the A-weighted decibel (dBA).
When sound levels increase, daily listening time becomes an important risk factor for hearing loss. In general, the louder the sound, the less time it takes to impact your hearing:
- Noise at, or above, 85 dBA over a prolonged period of time may start to damage your hearing.
- Loud noise above 120 dBA can cause immediate harm to your ears.
Risky noise exposure can cause the following symptoms after a loud noise has stopped:
- a temporary hearing loss – sounds seem muffled, quieter or less clear
- tinnitus – a ringing, buzzing, roaring or rushing sound in the ear, which has no source outside the ear
Although these symptoms may stop after a few hours, research suggests that there may be residual long-term hearing damage. If these symptoms continue after 24 hours, please consult your physician.
Noise Adds Up
It’s been found that a variety of everyday activities can cause exposure to sound levels above 85 dBA. A few examples are:
- listening to music through headphones or earbuds
- attending a rock music concert
- mowing the lawn
- using a table saw
- driving a car on the highway with the windows open
- playing a musical instrument
- participating as a member of a band or orchestra
If you’re exposed to these noises for short periods of time without ear protection, you might think you’re in the clear, but noise exposure adds up.
Let’s say you listen to music through a speaker for 1 hour during the day at 93 dBA. Then later that night, without ear protection, you spend just 10 minutes using a table saw at 100 dBA. Each activity, on its own, is not quite enough to cause a significant risk of a gradual, permanent noise-induced hearing loss, but on the same day, your total noise exposure crosses a safe threshold.
How Can I Prevent Noise-Induced Hearing Loss?
Limit Loud Activities: Reduce time spent on extremely noisy activities.
Adjust Audio Levels: Keep car and home audio at enjoyable yet safe levels.
Use Ear Protection: Wear well-fitted earplugs or earmuffs in noisy environments. Consult an audiologist for advice.
Take Quiet Breaks: Schedule quiet time if you experience temporary hearing loss or tinnitus. Let your ears fully recover.
Choose Safe Toys for Children: Avoid loud toys; opt for those with volume control or an on-off switch. Children may hold toys close to their ears.
Monitor for Early Signs: Pay attention to signs like trouble following conversations in noisy settings, perceived mumbling, or tinnitus. Consult your doctor if you’re concerned.
Remember- prevention is the only way to protect yourself from Noise-Induced Hearing Loss. There is no way to know how sensitive your ears are to damage from sounds until the damage is done.
Tinnitus
Tinnitus, affecting 10 to 15 percent of adults, presents as ringing, buzzing, or pulsing noises in the ear. Often linked to hearing loss, managing the hearing loss with aids can reduce tinnitus effects. While occasional tinnitus is normal, constant tinnitus can lead to stress, anxiety, and other challenges. If you’re among the 5% experiencing severely intrusive tinnitus, therapeutic approaches and support groups can provide assistance.
Hyperacusis, impacting 5% of the population and 50% of those with tinnitus, is an increased sensitivity to everyday sounds, causing discomfort or pain. Examples include alarms, clanging dishes, and children crying. Therapeutic approaches and support groups are available for those dealing with hyperacusis.
Speak to an audiologist if you’re experiencing tinnitus or hyperacusis.
Auditory Processing Disorders
Auditory processing disorders (APD) are often investigated in children labeled as ‘poor listeners,’ who may have normal hearing but struggle to connect what is heard with what is understood. Although currently a prominent concern for school-aged children, APD also occurs in adults. Diagnosing APD is challenging as routine hearing tests do not identify it; advanced testing is necessary. Adults with APD face difficulties in interpreting sounds, impacting listening, learning, and memorization. If you suspect APD, reach out to your family physician or audiologist.
