Causes Of Hearing Loss In Adults
Hearing loss, also known as hearing impairment or deafness, is the total or partial inability to hear sounds. Hearing loss may be temporary or permanent, with mild, moderate, severe, or profound symptoms.
People with mild hearing loss often have difficulty understanding speech when there is a lot of noise, while those with moderate hearing loss will need to use hearing aids to understand speech.
On the other hand, people with severe hearing loss may need to rely on lip-reading when communicating, while those with profound hearing loss can hear nothing at all and will be heavily dependent on sign language and lip-reading for communication.
Hearing loss can affect one or both ears. The effect of hearing loss isn't just restricted to your ability to hear; rather, it can affect the ability to acquire spoken language in children and difficulties with communication and social interactions in adults.
Types of Hearing Loss
Hearing loss is grouped into three major types; sensorineural, conductive and mixed hearing loss.
Sensorineural hearing loss occurs when the auditory nerve or the hair cells in the cochlea in the inner ear are damaged. The ear's sensitivity to sound decreases due to the damage, which affects the transmission of sound to the brain for interpretation.
Conductive hearing loss, on the other hand, occurs when the outer and middle ear is abnormal. This abnormality prevents the natural flow of sound to the inner ear. Conductive hearing loss can be corrected by surgery or medication.
Mixed hearing loss is the combination of both conductive hearing loss and sensorineural hearing loss. This means that damage has been done to the outer ear, middle ear, and inner ear.
Mixed hearing loss is often permanent because even though conductive hearing loss can be treated, sensorineural hearing loss is often permanent, especially if the hearing loss is caused by damage to the inner ear’s hair cells.
The causes of hearing loss are either congenital or acquired. Congenital causes are factors that cause hearing loss in children at birth, while acquired causes are factors responsible for hearing loss in adults.
Acquired causes are responsible for the majority of hearing loss cases in adults.
In this post, we will be examining the causes of hearing loss in adults. But before we get started, let's briefly look at common symptoms of hearing loss in adults.
Symptoms of Hearing Loss
Here are some symptoms of hearing loss:
- Difficulty hearing consonants: This is especially true for people with mild and moderate hearing loss. Some people may be able to hear vowel sounds, but others are unable to pick vowel sounds.
- Muffling of sound and speech: In some cases, muffled speech doesn't just happen when the sound is low; it also happens with normal level or loud sounds.
- Asking for repetition: Constantly asking for repetition during a conversation or asking the other person to speak loudly is a common hearing loss symptom.
- Inability to understand speech: Difficulty understanding words or speech in a crowded place or when there is background noise.
- Volume increase: Turning up the radio or television volume to be able to comprehend what is being said. This is often accompanied by the difficulty of hearing the person on the other end of a telephone call.
- Conversation withdrawals: Withdrawal from conversations and avoidance of social settings.
Causes of Hearing Loss in Adults
As stated earlier, most causes of hearing loss in adults are acquired. Below are some common causes of hearing loss in adults.
1. Exposure to Loud Noise
Sudden or extended exposure to loud noise can cause hearing loss. When your ears are exposed to loud noise, the hair cells in the inner ear, which are responsible for hearing, can be flattened or damaged.
If the hair cells are just flattened, the hearing loss will be temporary, but if the hair cells were damaged, the hearing loss is permanent because damaged hair cells cannot be repaired or replaced.
According to the Environmental Protection Agency, 70 decibels is the safe noise level for people. The louder the noise beyond the safe level, the lesser time it takes to cause permanent hearing damage.
The sound level of normal conversation is 60 decibels, while that of a dishwasher is 75 decibel. 75 decibels is still considered to be within the safe range. Sound levels from 85 and above are considered risky. Noise from heavy traffic (85 dB), sandblasting (115 dB), snowmobile (100 dB), firecrackers, and firearms (140-165 dB) can do serious damage to your ear.
Due to the danger of extended exposure to loud noise, maximum sound exposure durations should not be exceeded. While we advise you to stay away from loud noise, certain occupations like the military and jobs involve the use of heavy equipment and firearms that constantly expose you to loud noise. This is why these maximum sound exposure durations exist.
The higher the sound level, the lesser the daily duration of exposure. For instance, exposure to a sound level of 90 decibels should not exceed 8 hours, 95 decibels is restricted to 4 hours, 100 decibels should not exceed 2 hours, while 110 decibels should be restricted to 30 minutes daily, and exposure to 115 decibels should be restricted to fifteen minutes or less daily.
Despite this recommended duration of exposure to the different sound levels, you must constantly wear hearing protection. This will reduce your chances of losing your hearing. However, even with hearing protection, continued exposure to loud noise will eventually take a toll on your ears.
Asides from occupational noises in the work environment, constant exposure to recreational activities with extremely high noise levels can also cause hearing loss. Activities such as snowmobiling and motorcycling can cause hearing loss.
Noise from clubs, concerts, and listening to loud music with headphones or earpieces can also cause hearing loss.
Presbycusis is the term used to refer to hearing loss caused by aging. Presbycusis is often sensorineural, and it happens when the structures of the inner ear begin to degenerate.
This degeneration is the cumulative effect of age and the exposure of the ear to loud sounds over time.
Age-related hearing loss is often characterized by difficulty in understanding speech. The speech begins to sound unclear or muffled, and there is also difficulty understanding high-pitched sounds.
Hearing loss caused by aging is gradual and may not be evident at the onset. Because it is progressive, you may not realize it until you begin to experience obvious symptoms like asking for repetition or increasing the volume of television or radio beyond the normal level.
Age-related hearing loss often affects both ears and is usually permanent. This is because hearing loss is caused by the degeneration of the hair cells in the inner ear. These hair cells cannot be regenerated or repaired once they are damaged. With the use of hearing aids, you may still be able to hear.
3. Tympanic Membrane Perforation
This is commonly known as a ruptured eardrum. The eardrum is a thin cone-shaped membrane that separates the middle ear from the external ear. It is responsible for the transmission of sound from the air to the ossicles in the middle ear and the oval window in the cochlea.
The conversion and amplification of vibration in the air to vibration in the cochlear fluid is the eardrum’s sole responsibility.
It is, therefore, not surprising that damage to the eardrum can cause hearing loss.
Sudden changes in pressure can cause this damage, sudden exposure to loud noise, poking the ear with an object, or an ear infection.
4. Ototoxic Medications
These are medicines used to treat other health conditions that can cause hearing loss. Many prescription and non-prescription drugs are ototoxic; this is why you should talk with your doctor before taking any medication.
Most ototoxic drugs cause tinnitus before they degenerate to hearing loss. In most cases, if the drug is discontinued, the hearing loss will disappear, especially if no serious damage was done to the ear.
Some drugs that can cause hearing loss include the following: high dose of aspirin, antibiotic gentamicin, viagra, antimalarial drugs, Aminoglycoside antibiotics such as kanamycin, streptomycin, or neomycin, certain anticancer chemotherapy drugs, painkillers, and loop diuretics such as ethacrynic acid and Lasix.
5. Certain Ear Diseases
Several ear diseases can cause hearing loss. Let's examine the three most common ear diseases responsible for hearing loss.
- Otosclerosis: This is a disease that affects the middle ear. Otosclerosis makes it difficult for the tiny bones (ossicles) in the middle ear to move. This prevents the transmitting of sound from the middle ear to the inner ear. Otosclerosis causes conductive hearing loss, and it can be corrected with surgery.
Autoimmune inner ear disease: Autoimmune inner ear disease is a medical condition that causes the body to begin to attack the ears. The attack is similar to how the body will react to a disease in the body. The victim of this attack is the hair cells in the inner ear.
Autoimmune inner ear disease happens fast, so if immediate medical care is not given, the hearing loss can be profound. However, with immediate medical treatment, some hair cells may be spared, and the hearing loss will be minimal.
Ménière's disease: This is an inner ear disease with an unknown cause. Meniere's disease often results in sensorineural hearing loss, which will come and go at the initial stage and, overtime becomes permanent.
Meniere’s disease’s common symptoms are sensitivity to loud sounds, dizziness, and ringing in the ear.
6. Other Causes
Hearing loss in adults can be caused by a lot of other factors such as ear infection, abnormal bone growths, tumors, acoustic neuroma, earwax buildup, and physical head injury.
Diseases or illnesses associated with high fever such as meningitis can also damage the cochlea and cause hearing loss.
If you suspect that something is wrong with your ears, don't wait until you begin to experience hearing difficulties before seeking medical attention. No sign or symptom should be ignored.
Avoid any form of self-medication. Every problem with your ears should be reported to your doctor, and only use drugs that the doctor prescribes.
Avoid activities such as cleaning your ears with sharp objects or exposure to loud noise. These can affect your hearing immediately or in the long run.
Do you have hearing loss? What do you think caused the hearing loss?