Top 8 Common Causes of Deafness: From Birth to Age-Related Changes

Hearing loss is a complicated condition with many different causes that can affect people at any age. If you are looking for information about the "causes of deafness," you probably want clear answers for yourself or someone you care about. This guide will give you those answers. Hearing loss is not the same for everyone - it can range from having trouble hearing some sounds to complete deafness. We will use respectful language, talking about "people with hearing loss" and recognizing the cultural identity of the Deaf community.

This article gives you a complete overview of why hearing loss happens. We will look at how hearing works, explain the causes that can be present from birth, examine the many things that can lead to hearing loss over time, and discuss what important steps to take if you have concerns. Our goal is to give you a trustworthy, expert resource to help you understand this important health topic.

How Hearing Works

To understand the causes of hearing loss, you first need to know the basics of how your hearing system works. The process of hearing is an amazing three-step process that changes sound waves in the air into meaningful information in your brain. A simple picture of the ear helps you see these parts clearly.

1. The Outer Ear: The part of your ear you can see, called the pinna, works like a satellite dish to collect sound waves from around you. It sends these waves down the ear canal to the eardrum.

2. The Middle Ear: When sound waves hit the eardrum, it shakes back and forth. These movements get passed to and made stronger by three tiny, connected bones: the malleus (hammer), incus (anvil), and stapes (stirrup). This energy then moves to the entrance of the inner ear. Think of this part as the system's amplifier.

3. The Inner Ear: The vibrations enter the cochlea, which is shaped like a snail and filled with fluid. Inside the cochlea are thousands of tiny hair cells called stereocilia. The fluid moves because of the vibrations, making these hair cells bend. This bending changes the vibrations into electrical signals. The auditory nerve carries these signals to the brain, which understands them as sound - whether it's speech, music, or a warning siren. Damage to any part of this delicate system can cause hearing loss.

Congenital Hearing Loss Causes

Congenital hearing loss is present at birth or develops very soon after. It is a big concern for families, and understanding what causes it is the first step toward managing it well. The causes are split about evenly between genetic and non-genetic factors. Newborn hearing tests, which are standard in most hospitals, are very important for finding problems early and getting help quickly.

Genetic Factors

According to the Centers for Disease Control and Prevention (CDC), genetic factors cause more than 50% of all cases of congenital hearing loss. The genetics of hearing are very complex, with hundreds of different genes playing a role.

• Non-syndromic Hearing Loss: This is the most common form, making up about 70% of genetic cases. In this situation, hearing loss happens by itself, without any other health problems. A person can have parents with perfect hearing who both carry a hidden gene for hearing loss.
• Syndromic Hearing Loss: In the remaining 30% of genetic cases, hearing loss is one part of a larger medical syndrome. These syndromes include other signs and symptoms. Examples include Usher syndrome, which also affects vision; Waardenburg syndrome, which can affect the color of skin, hair, and eyes; and Down syndrome, which often includes hearing problems.

Pregnancy and Birth Factors

The other half of congenital cases happen because of non-genetic factors that occur during pregnancy or around the time of birth. The developing hearing system is easily damaged during this time.

• Infections During Pregnancy: Some infections that mothers get can cross the placenta and damage the baby's developing hearing system. The most common of these is cytomegalovirus (CMV). Others include rubella (German measles), toxoplasmosis, and herpes.
• Premature Birth and Low Birth Weight: Babies born very early often have organs and systems that aren't fully developed, including the hearing system, which puts them at higher risk for hearing loss.
• Birth Problems: Events that keep a newborn from getting enough oxygen, called birth asphyxia, can damage the brain and the delicate parts of the inner ear.
• Severe Jaundice: Very high levels of bilirubin in a newborn can lead to brain damage called kernicterus, which is known to cause hearing loss.

Acquired Hearing Loss Causes

Acquired hearing loss is any hearing loss that develops after birth. It can happen at any point in life, from childhood to old age, and has many different causes. This is the most common type of hearing loss, including a wide range of environmental, medical, and age-related factors.

Age-Related Hearing Loss

Also called presbycusis, age-related hearing loss is a gradual decline in hearing that is one of the most common conditions affecting older adults. The National Institute on Deafness and Other Communication Disorders (NIDCD) reports that about one in three people in the United States between the ages of 65 and 74 has hearing loss.

This decline usually happens because of changes that build up over time in the inner ear and auditory nerve pathways. Over a lifetime, the delicate hair cells in the cochlea can become damaged or die and are not replaced. Often, the first sign is trouble hearing high-pitched sounds, like the voices of women and children, or difficulty understanding speech in noisy places. Because it happens slowly, many people don't notice it until it becomes significant.

Noise-Induced Hearing Loss

Noise-induced hearing loss (NIHL) is the only major cause of hearing loss that is almost completely preventable. It happens from being around sounds that are too loud, which damages the sensitive stereocilia in the inner ear. This damage can be caused by:

• A single, very loud sound: An explosion, gunshot, or firework close to the ear can cause immediate and permanent damage.
• Continuous or repeated exposure to loud sounds over time: This is more common and sneaky. Jobs like construction, manufacturing, and farming, or fun activities like going to concerts, listening to music through headphones at high volumes, and using power tools can all contribute to NIHL over months or years.

Sounds are measured in decibels (dB). Long exposure to any noise at or above 85 dB can cause gradual hearing loss. A normal conversation is around 60 dB. A motorcycle is about 95 dB, and a rock concert can easily reach 115 dB or more, where damage can happen in less than a minute.

Illnesses and Infections

Many different illnesses and infections can directly or indirectly lead to hearing loss, which can be temporary or permanent.

• Chronic Ear Infections (Otitis Media): Fluid that stays in the middle ear can cause conductive hearing loss and, if left untreated for long periods, can sometimes lead to permanent damage.
• Otosclerosis: This is a condition where abnormal bone growth happens in the middle ear, specifically around the stapes bone. This growth stops the bone from moving properly and sending sound to the inner ear.
• Ménière's Disease: This is a disorder of the inner ear that causes episodes of vertigo (dizziness), tinnitus (ringing in the ear), a feeling of fullness or pressure in the ear, and hearing loss that goes up and down but can become permanent over time.
• Viral and Bacterial Infections: Serious infections like bacterial meningitis and viral infections such as measles or mumps can cause severe sensorineural hearing loss by damaging the cochlea or auditory nerve.
• Autoimmune Inner Ear Disease (AIED): In this rare condition, the body's immune system mistakenly attacks the cells of the inner ear, leading to rapidly worsening hearing loss.

Physical Trauma and Injury

Physical injury to the head or ear can cause hearing loss. A severe head injury can damage the temporal bones that contain the inner and middle ear structures or disrupt the auditory nerve pathways. A direct hit to the ear or a sudden change in pressure, such as from flying or scuba diving, can cause a hole in the eardrum, which usually heals but can sometimes lead to problems.

Medications That Damage Hearing

The term "ototoxic" means poisonous to the ear. A number of medications, while necessary for treating serious health conditions, can have the unwanted side effect of damaging the inner ear, resulting in hearing loss, tinnitus, or balance problems. The damage can be temporary or permanent. It is very important to discuss the risks and benefits of these medications with a healthcare provider.

| High-Dose Salicylates | Aspirin | Hearing loss and tinnitus are typically associated only with very high, long-term doses and are often reversible. |

The Interplay of Factors

It is a common mistake to think that hearing loss comes from a single, identifiable cause. In reality, it is often the result of a complex mix of multiple factors. A person's unique genetic makeup, lifestyle, and health history combine to create their individual risk profile. This cumulative effect is an important concept in understanding why and how hearing loss gets worse.

Consider a person with a known family history of age-related hearing loss. This suggests a genetic tendency. If that same person then spends their career working in a loud factory without consistent hearing protection, the noise exposure can speed up the underlying genetic tendency. Their hearing loss may begin at an earlier age and get worse more quickly than it would for someone who had only one of these risk factors.

This combined effect can also be seen with medications that damage hearing. A patient receiving a drug like cisplatin for cancer treatment may be at a higher risk of severe hearing loss if they also have an existing hearing condition or are at the same time exposed to loud noise. Understanding this interaction is vital for both prevention and personalized management strategies. It shows the importance of a complete health history when evaluating hearing loss.

Recognizing the Signs

The journey toward addressing hearing loss often begins not with sudden silence, but with a series of subtle, building moments of difficulty. The change can be so gradual that it's friends and family who notice it first. Understanding these early signs is the first step toward taking action.

Many people first notice a change not in themselves, but in their interactions. A common experience shared in our clinics and support groups is the feeling of being left out of conversations. You might find yourself constantly asking others to repeat themselves, or turning the TV volume up to a level that others find uncomfortable. You may begin to struggle with phone conversations or find that you mishear words, mistaking "fifty" for "sixty." Social gatherings, especially in noisy restaurants, can become exhausting and frustrating.

If these experiences sound familiar, it is a clear signal to seek a professional evaluation. Here is a straightforward path to follow:

1. Consult Your Primary Care Physician: Start by discussing your concerns with your family doctor. They can rule out simple, fixable causes like earwax buildup or an ear infection and provide a referral to a specialist.
2. See an Audiologist: An audiologist is a healthcare professional who specializes in diagnosing, managing, and treating hearing and balance disorders. They are the primary experts for a complete evaluation.
3. Get a Hearing Evaluation: This is a painless, non-invasive process. The audiologist will do a series of tests, often in a sound-treated booth. The primary test, an audiogram, measures your ability to hear sounds at different pitches and volumes. The results will precisely map your hearing ability and determine the type, degree, and pattern of any hearing loss.

Prevention and Management

While not all causes of hearing loss can be prevented, some of the most common ones can. For hearing loss that has already happened, a wide range of effective management strategies exists to improve quality of life.

Protecting Your Hearing

Taking action ahead of time can significantly reduce your risk of developing noise-induced and other forms of preventable hearing loss.

• Wear hearing protection, such as earplugs or earmuffs, when you are in a loud environment.
• Lower the volume on personal listening devices and follow the 60/60 rule: listen at no more than 60% of the maximum volume for no more than 60 minutes at a time.
• Take "listening breaks" to give your ears a rest from continuous noise.
• Choose quieter appliances and entertainment venues when possible.

Managing Hearing Loss

A diagnosis of hearing loss is not an endpoint; it is the beginning of a journey toward better hearing and communication. An audiologist will help determine the best path forward for your specific needs.

• Hearing Aids: Modern digital hearing aids are sophisticated devices that can be programmed to amplify the specific frequencies you have trouble hearing.
• Cochlear Implants: For individuals with severe to profound sensorineural hearing loss, a cochlear implant may be an option. It is a surgical device that bypasses the damaged part of the inner ear and directly stimulates the auditory nerve.
• Assistive Listening Devices (ALDs): These devices can help in specific situations, such as personal amplifiers, TV listening systems, and alerting devices.

Conclusion

The causes of deafness and hearing loss are numerous and varied, coming from genetics, illness, noise, age, and a combination of these factors. The hearing system is complex, and its function can be disrupted at many points. If you have any concerns about your hearing or that of someone you care about, the single most important action you can take is to seek a professional medical evaluation. Understanding the cause is the crucial first step toward effective management, protecting your remaining hearing, and continuing to live a full and connected life.