Types of Deafness Explained: From Conductive to Sensorineural Hearing Loss

Introduction: Understanding Your Hearing

Getting a hearing loss diagnosis for yourself or someone you care about can feel scary and confusing. Suddenly, you're hearing new medical words and worrying about what comes next. We want you to know that you've come to the right place for clear, trustworthy answers. Understanding what kind of hearing loss you have is the first and most important step to dealing with it well.

Hearing loss isn't just one thing. Doctors divide it into three main groups: conductive, sensorineural, and mixed. There's also a fourth, less common type called Auditory Neuropathy Spectrum Disorder. These groups are based on one simple but important question: which part of your hearing system isn't working right?

Our goal is to give you a complete guide that makes these confusing terms easy to understand. We'll explain each type of hearing loss, what causes it, and what it feels like. We'll use the term Deaf / Hard of Hearing to respectfully talk about the diverse group of people with hearing loss. By the end, you'll have a strong understanding of your diagnosis and be ready to talk about next steps with your doctors.

How We Hear

To understand hearing loss, it helps to first understand how hearing works. Think of your hearing system like a relay race with three parts, where sound travels from your outer ear, through your middle ear, to your inner ear, and finally to your brain.

1. The Outer Ear: This includes the part of your ear you can see (the pinna) and the ear canal. Its job is like a funnel, catching sound waves around you and sending them toward your eardrum.

2. The Middle Ear: This is a space filled with air behind your eardrum. When sound waves hit your eardrum, it shakes back and forth. These shakes get passed along and made stronger by three tiny connected bones called ossicles (the malleus, incus, and stapes). The middle ear's job is to change sound waves in the air into mechanical vibrations.

3. The Inner Ear: The last stop is the cochlea, which looks like a snail shell and is filled with fluid. The vibrations from the middle ear make waves in this fluid. These waves move tiny hair cells inside the cochlea, which change the vibrations into electrical signals. The auditory nerve then carries these signals to your brain, which understands them as the sounds you recognize.

When any part of this complex system gets blocked, damaged, or stops working right, hearing loss happens.

Deep Dive: Conductive Loss

What is It?

Conductive hearing loss happens when there's a problem in your outer or middle ear. This problem stops sound from getting through effectively to your inner ear. Your inner ear is healthy and ready to work, but the sound signal it gets is too weak.

A good comparison is a high-quality stereo with a muted or blocked speaker. The music is playing, but the sound can't get out properly. For someone with this type of hearing loss, sounds seem too quiet, weak, or muffled. The problem is with the volume, not how clear the sound is.

Common Causes

Many causes of conductive hearing loss are temporary and can be fixed by doctors. This is different from other types of hearing loss. Common causes include:

• Fluid in the middle ear, which happens a lot in children
• Blockage in the ear canal from earwax
• Middle ear infections, which cause swelling and fluid buildup
• A torn eardrum from injury, infection, or pressure changes
• Otosclerosis, when one of the tiny middle ear bones gets stuck and can't vibrate properly
• Non-cancerous tumors or growths
• Structural problems with the outer or middle ear that people are born with

What It Feels Like

From someone's personal experience, conductive hearing loss often makes the world sound like you're hearing it from underwater. Outside sounds are weak and hard to make out. Interestingly, a person's own voice may sound unusually loud to them because it travels to the inner ear through the bones in their skull, going around the blockage in their outer or middle ear.

For example, someone with ongoing middle ear fluid might say that conversations sound muffled, making them ask people to speak louder, even when they know the other person is speaking at normal volume. They might turn up the TV volume a lot just to follow what's being said.

Treatment Options

An important thing about conductive hearing loss is that it can often be fixed. If the cause is earwax, an infection, or fluid, medical treatment can often bring hearing back completely. In cases like otosclerosis or a damaged eardrum, surgery can work very well.

For permanent conductive hearing loss, or for people who can't have surgery, treatment options include regular hearing aids or bone-anchored hearing systems, which go around the outer and middle ear to send sound vibrations straight to the inner ear.

Deep Dive: Sensorineural Loss (SNHL)

What is SNHL?

Sensorineural hearing loss is the most common type of permanent hearing loss. It happens when the delicate parts of the inner ear (the cochlea) or the auditory nerve that connects the cochlea to the brain get damaged.

Using our stereo comparison, SNHL is like having broken microphones inside the cochlea or a damaged cable going to the brain. The sound gets to the inner ear, but the system for changing it into a clean electrical signal and sending it to the brain is broken. This damage causes not only a loss of volume but, more importantly, a loss of clarity.

Hear But Can't Understand

A common phrase used by people with SNHL is, "I can hear you, but I can't understand what you're saying." This shows the main problem: a loss of clarity. While sounds may be heard, they are often distorted and unclear.

This happens because damage to the inner ear's hair cells is often uneven, affecting the ability to hear certain frequencies (pitches) more than others. High-frequency sounds, which are important for telling apart consonants like 's', 'f', 't', and 'sh', are usually the first to be lost. As a result, words like "cat," "hat," and "sat" can sound the same. This makes understanding speech very hard, especially in places with background noise.

Common Causes

According to the World Health Organization, over 5% of the world's population—or 430 million people—need help to deal with their hearing loss, with SNHL being the main cause. Unlike many conductive losses, SNHL is usually permanent. The most common causes are:

• Aging: This is a gradual decline in hearing that happens as we get older
• Noise Exposure: Long exposure to loud sounds or one-time exposure to an extremely loud blast (like an explosion) can permanently damage the hair cells
• Genetics: Many forms of hearing loss run in families
• Harmful Medications: Certain drugs, including some strong antibiotics and chemotherapy drugs, can be toxic to the inner ear
• Illnesses and Infections: Viruses like measles and meningitis can cause SNHL
• Head Trauma: A serious injury to the head can damage the inner ear structures

Management Options

While SNHL can't be "cured" or reversed with medicine or surgery, it can be managed very well. The main goal of management is to make sound audible and, more importantly, clearer.

The most common solution is a well-fitted hearing aid. Modern digital hearing aids are advanced devices that can be programmed to amplify only the specific frequencies a person has lost, improving speech clarity. For people with severe to profound SNHL who get little help from hearing aids, a cochlear implant may be an option. A cochlear implant is a surgical device that goes around the damaged hair cells and directly stimulates the auditory nerve.

Deep Dive: Mixed & Other Types

Mixed Hearing Loss

As the name suggests, mixed hearing loss is a combination of both conductive and sensorineural hearing loss. This means there's a problem in the outer or middle ear, as well as damage to the inner ear or auditory nerve.

On an audiogram (a hearing test graph), mixed hearing loss shows the characteristics of both types. A clear example is an older adult who already has age-related sensorineural hearing loss and then gets a middle ear infection with fluid. The underlying SNHL causes a permanent loss of clarity, and the conductive part adds a temporary loss of volume. Treatment for mixed hearing loss involves dealing with both issues—managing the conductive part medically or surgically if possible, and supporting the sensorineural part with hearing aids.

Auditory Neuropathy

Auditory Neuropathy Spectrum Disorder (ANSD) is a less common but important type of hearing loss. In ANSD, the outer, middle, and even the inner ear (the cochlea's hair cells) can be working perfectly. Sound is detected normally. The problem is in sending the signal from the inner ear to the brain. The auditory nerve fails to send a clear, synchronized message.

The experience of someone with ANSD can be very challenging. Their hearing ability can change from day to day. They may pass a simple hearing screening that only tests for sound detection, but they have extreme difficulty understanding speech. For these people, making sounds louder with a hearing aid may not help with clarity and can sometimes make it worse. Management often focuses on visual communication strategies (like sign language) and, in some cases, cochlear implants.

Comparing the Types

To help summarize and clarify the key differences, this table breaks down the three main types of hearing loss side-by-side.

Beyond the Type

A diagnosis from an audiologist will include more than just the type of hearing loss. To get a complete picture, they will also describe how severe it is and its pattern. This gives a more complete and person-centered understanding of someone's unique hearing profile.

Degrees of Loss

The degree describes how severe the hearing loss is, measured in decibels (dB). It tells you "how much" hearing is lost.

• Mild: Hard to hear soft sounds like whispers or distant conversations. Following speech in a noisy room is challenging.
• Moderate: Hard to hear normal conversation. The TV volume is often turned up high.
• Severe: Can only hear loud speech or loud environmental sounds like a vacuum cleaner or a dog barking. Normal conversation can't be heard without amplification.
• Profound: May only feel very loud sounds as vibrations. Speech can't be heard. People in the Deaf community often have hearing loss in this range.

Configuration Patterns

Configuration describes the pattern of hearing loss across different frequencies and between the two ears.

• Unilateral vs. Bilateral: This is one of the most important differences. Unilateral hearing loss means the loss is in one ear only, while bilateral means it affects both ears. From a personal experience perspective, unilateral hearing loss presents unique challenges. Finding where a sound is coming from is very difficult, and hearing in group settings or noisy environments is exhausting because the "good" ear is doing all the work.
• Symmetrical vs. Asymmetrical: Symmetrical means the hearing loss is the same in both ears. Asymmetrical means the degree or type of loss is different between the two ears.

What to Do Next

Understanding these terms is an important step, but it doesn't replace professional medical advice. Self-diagnosis isn't reliable, and a complete evaluation is the only way to get an accurate picture of your hearing health.

The Audiologist's Role

An audiologist is a healthcare professional who specializes in diagnosing, treating, and managing hearing loss and balance disorders. They will do a complete hearing test to create an audiogram—a graph that maps out your hearing ability. This test will determine the exact type, degree, and configuration of your hearing loss. This information is essential for creating an effective management plan.

Finding Support

A hearing loss diagnosis can feel isolating, but you are not alone. Open communication with your family, friends, and healthcare providers is important. There are also many resources and active communities for Deaf and Hard of Hearing people that offer information, advocacy, and peer support.

Your path forward can be broken down into clear, manageable actions:
1. If you think you have hearing loss, schedule a complete hearing test with an audiologist.
2. Take time to discuss the results with your audiologist. Ask questions until you feel you understand your diagnosis.
3. Explore the recommended management options, whether they are medical treatments, hearing aids, or other assistive technologies and communication strategies.