Hearing loss refers to a sudden or gradual loss of partially or completely hearing or perceiving sound. The ear cannot absorb sound and transport it through the nerves to the brain where the sound interpretation occurs. Hearing loss drastically affects an individual’s life and may make a person unable to socially fit in or normally interact with people due to the communication barrier.
This article highlights the hearing process, types of hearing loss, and what causes them. The detailed breakdown will help you identify signs and symptoms of gradual hearing loss and provide guidance on what stags to seek help, ensuring you catch the early signs and get help for your loved one.
The hearing processes
The ear is divided into three main parts;
• The outer ear
• Middle ear
• Inner ear
The hearing process starts with sound waves entering the outer ear and traveling to the eardrum. The eardrum, a thin piece of skin located between the outer and inner ear, vibrates when hit by sound. The eardrum works closely with the ossicles, which makes up the middle ear to increase vibration further as the sound waves pass on to the inner ear.
Sound in the inner ear travels through the cochlea’s fluids, a snail-shaped organ, and into the nerve cells containing numerous small hairs that convert sound into electrical signals and send the signals to the brain. The brain then interprets the electrical waves into sound and helps you process the information. The cochlea section’s hair reacts differently to different types of sounds sending various information to the brain.
Types of hearing loss and their causes
The three types of hearing loss are;
• Conductive hearing loss
• Sensorineural hearing loss
• Mixed hearing loss
1. Conductive hearing loss
Conductive hearing loss is the hearing impairment that occurs from the inability of sound waves to travel through the outer ear, the tympanic membrane, and the ossicles. This type of hearing challenge makes it hard for a person to hear a soft sound.
Symptoms of conductive hearing loss
The symptoms of conductive hearing loss vary depending on the extent and severeness but include;
• Steady or sudden hearing loss
• Pain in the ear
• Muffled hearing
• A stuffy feeling in the ear
Conductive hearing loss occurs when the sound gets hindered from reaching the inner ear to its full extent. The external ear structure may be affected by;
• Otitis externa – this is a condition caused by continual exposure to water. It mainly affects swimmers and divers who spend too much time in the water. It is an infection that affects the ear canal and may occur due to excessive ear swabs that erodes the good wax; the ear needs to function properly.
• Earwax- abnormal or excessive production of ear wax by your body, which builds up in the ear canal instead of migrating to the concha or ear bowl, may block or affect normal hearing making it hard for a person to synthesize soft or gentle sound.
• Bony lesions- refers to growth found in the ear’s external parts, often associated with frequent swimming in cold water that provides an environment for the lesions to grow, impairing your hearing.
• Aural atresia – this is a congenital disability that refers to the absence of the ear canal and affects the ear’s external structure, leading to conductive hearing loss and challenges.
• Microtia – refers to the combination of an underdeveloped or undeveloped pinna that leads to hearing difficulties or loss. It affects 1 in 10,000 births in the world and can either be unilateral or bilateral.
• Foreign body- refers to a foreign object caused by accidents in adults or placement of a foreign object into the ear by children.
Conductive loss issues associated with the middle ear structure;
This infection affects the middle part of the ear, making it inflamed and filled with fluid. The fluid replaces the air in the section making it hard for one to hear and make out the sound. Otitis media occurs in three stages where the acute otitis media refers to active infection in the middle ear section that is painful and characterized by fever.
Fluid found in the middle ear with the absence of infection is referred to as serous otitis media. Chronic otitis media refers to a lasting discharge of fluid from the ear and damage to the ossicles leading to inability to process sound.
The collapse of the eardrum
The middle ear’s sudden pressure changes or imbalance may lead to the eardrum collapsing onto the middle ear. Causes of eardrum collapse may be extreme sports that involve a change of pressure such as jet flying and bungee jumping or hiking.
Cholesteatoma refers to the abnormal growth of skin cells in the middle ear space that may form lumps, causing pressure and damage to the bones.
Hole in the drum
Infection, accidents, or trauma may lead to the formation of a hole in the tympanic membrane. Malfunctions in the Eustachian tube or its weakening may also lead to a hole in the eardrum.
Otosclerosis is a genetic type of disease that occurs more in women than men. Characterized by the connection of bones in the middle ear growing and connecting with those around it, it can’t vibrate and pick up sound or hinder the smooth vibration process. Otosclerosis may also get experienced as an abnormal growth of bone on either three bones of the middle ear: the Malleus, stapes, or incus.
Refer to the formation of non-cancerous tumors affecting both the external and middle ear section that may hinder the hearing process. Benign tumors block the outer or inner ear preventing the transfer of sound waves into electrical signals.
Treatment of conductive hearing loss
i. Surgery corrects several conductive hearing loss causes such as otosclerosis, malformation, congenital absence of ear canal, or failure to open during birth and head traumas or tumor removal.
ii. Use of antibiotics or antifungal medication to treat otitis media or otitis externa.
iii. Sound amplification that is corrected by surgery to insert a bone-conducted hearing aid or osteointegration.
2. Sensorineural hearing loss
This type of hearing loss is responsible for almost 90% of the hearing loss issues associated with adults. The condition arises from damage to the inner ear structure or nerve pathways to the brain. SNHL is usually known as nerve deafness and makes even distinct loud noises seem muffled or whispered. Damage to the auditory nerve hinders the nerve signal transportation of sound to the brain. The degree of SNHL may vary depending on the damage degree.
Sensorineural hearing loss gets classified into three types: bilateral, which affects both ears, unilateral that affect one ear, or asymmetrical that affects both sides, one being worse than the other.
• Muffled sound or voices
• Trouble hearing with background sounds such as music
• Inability to understand what you are hearing
• Ringing sound in the ears
• Balance or dizziness issues
• Unable to hear high pitched sound such as women or children’s voices
Presbycusis refers to the gradual hearing loss that occurs as an individual gets older. This disease mainly affects individually aged 60 and above. Severneess of presbycusis varies among individuals, with some unable to hear high pitched tones like children or birds chirping while others cannot make out the typical gentle sound.
Exposure to loud noises above 85 decibels may weaken the inner ear leading to nerve damage. One-time loud noises may cause irreversible damage to your inner ear leading to SNHL. Also, continual exposure, for example, due to occupation such as farmers who use loud machines, pilots, or people working in factories exposed to loud noises, may have this issue over time.
The congenital disorder occurs from birth abnormalities such as otosclerosis, or malformation of the inner ear.
Virus or disease
Viral or bacterial infection can affect the inner ear damaging the nerves responsible for transmitting sound. The use of ototoxic medications may also damage the nerve cells leading to SNHL. Diseases such as Meniere’s that affect the inner ear may also affect balance and hearing.
Infections such as measles, mumps, scarlet fever, and meningitis can damage the cochlea’s nerves leading to SNHL. Various types of ENT cancers, such as acoustic neuroma, where a tumor grows on nerves that connect the ear to the brain or their treatment, can also lead to temporary or permanent SNHL.
Accidents or traumas to the head or skull may lead to nerve damage causing various degrees of SNHL. The use of or presence of sharp objects in the inner ear may also affect the nerves.
Treatments of Sensorineural hearing loss
i. Antibiotics and antibacterial medication can medically treat sudden SNHL caused by diseases or infections.
ii. Use of medication such as corticosteroids to treat inflammation or hair cell swelling in the cochlea due to exposure to loud noise
iii. Treatment of diseases such as the Meniere diseases by use of diet, medication or surgically
iv. Emergency surgeries occur to correct the inner ear’s damage, leading to fluid buildup and the eardrum’s rupture caused by sudden pressure imbalance in the inner ear.
v. Use of hearing loss aids to counter irreversible damage to the nerve cells in the cochlea area.
Mixed hearing loss
Mixed hearing loss is a hearing condition that combines sensorineural and conductive hearing loss and points to a problem in the ear’s outer, inner, and middle parts, injuring the auditory nerves. Mixed hearing occurs when the outer and inner ear cannot send sound waves, and the cochlea area cannot change sound waves into electrical signals that the brain can disseminate.
Causes of Mixed hearing loss
Mixed hearing loss include causes that bring about sensorineural hearing loss, such as genetic causes, drugs, head trauma, or illnesses. And those that cause conductive hearing such as cerumen, ear infection, fluid in the middle ear space, malformation of the outer or inner ear, and a perforated eardrum.
The symptoms of mixed hearing loss include
• Reduced hearing in one or both ears
• Pain in the inner ear section
• Discharge from the ear
• Ringing sound
• Inability to make out sound and understand what people are saying
Treatment of mixed hearing loss
The treatment plan for mixed hearing loss largely depends on whether the issue leans more to conductive or sensorineural type. If the issue is more to the conductive side, then surgical and medical measures are used to treat the malfunction and correct the hearing process. However, if the issue is more sensorineural, then identifying whether it is permanent or temporary influences action.
Most sensorineural causes are irreversible; thus, hearing aids get used to alleviate its adverse effects and enable the nerve cells in the cochlea to pick the sound vibrations easily. Mixed hearing loss treatment is thus a combination of surgical options and the use of hearing aids. If you suspect mixed hearing loss contact a doctor to ensure proper tests get conducted, and help is sort early. Taking care of the conductive issue first ensures the person is a better candidate for hearing aids and drastically improves their hearing ability.
Prevention options for hearing loss
• Hearing loss drastically affects the quality of your life. Most individuals affected by the condition find themselves frustrated and unable to communicate, making them stressed and over the edge. Hearing loss can thus cause anxiety, mental illnesses, and breakdowns due to the inability to appropriately communicate or interact with others. Some of the prevention measures one can use to reduce the causes of hearing loss include;
• Use of safety equipment if you work in areas that produce large amounts of noise. Safety equipment ensures you do not expose your ears to high sound decibels that gradually diminish your ears’ strength.
• Avoid prolonged exposure to loud noises or music, primarily through the use of earphones that have direct contact with your inner ear area.
• Ensure proper physical preparation before undergoing vigorous exercises, mountain climbing, or other activities that cause a sudden change of pressure to ensure you do not drastically alter the ear’s pressure level, damaging them.
• Regularly conduct a hearing test if you work in noisy factories, is an experienced swimmer, or frequently attends events with large noises.
• Ensure that ear infection is promptly looked into and prescribed medication appropriately issued to ensure ear infection treatment.
The causes of hearing loss can easily get identified and addressed to minimize effects. If you have young children, keenly focus on their behavior and reaction to sound and noise to help detect any malfunctions and have them dealt with early. It would help if you also led a lifestyle that protects your ears and minimizes exposure to noise and infection, leading to hearing loss.