Types of hearing loss

The four types of hearing loss, explained

The three most common types of hearing loss are sensorineural hearing loss (SNHL), conductive hearing loss, and mixed hearing loss.

However, Auditory Neuropathy Spectrum Disorder (ANSD) can also cause hearing loss or deafness.

• Sensorineural hearing loss (SNHL).  This type of hearing loss occurs in the inner ear and is most often associated with aging, trauma, disorders, or infections.
• Conductive hearing loss. This occurs when a problem or condition with the outer or middle ear causes hearing loss.
• Mixed hearing loss. When a patient experiences hearing loss due to issues in either the outer or middle ear, as well as the inner ear, it’s called mixed hearing loss.
• Auditory Neuropathy Spectrum disorder (ANSD). ANSD occurs when the inner ear or auditory nerve is damaged so that sound enters normally but cannot be understood.

Let’s look at each type of hearing loss, their causes and the treatment options available.

Sensorineural hearing loss

Sensorineural hearing loss is the type of hearing loss most people experience worldwide and is often caused by Trusted SourceNational Library of MedicineSensorineural Hearing LossGo to source underlying conditions. SNHL is also considered a natural and expected part of aging.

Causes of sensorineural hearing loss

SNHL can be caused by head injuries and noise-induced hearing loss. Noise-induced hearing loss can occur simply by listening to music too loudly for too long. There are other causes, though, that are more complex.

• Congenital. Hearing loss can be present at birth and associated with other symptoms (syndromic) or not (nonsyndromic).
• Aging. The medical term for natural hearing loss associated with aging is presbycusis.
• Medication. Certain medications, such as those used to treat cancer, autoimmune disorders, or powerful antibiotics, can cause SNHL.
• Health. Some conditions, like meningitis, Trusted SourceAdvancing the science of communication to improve livesSensorineural Hearing LossGo to source Meniere’s disease, certain autoimmunes, and diabetes, can lead to this type of hearing loss.
• Vestibular schwannoma. Also known as Trusted SourceExpert guidance for vestibular schwannomasNeurology and NeurosurgeryGo to source acoustic neuroma, this occurs when a benign tumor develops that interferes with balance and hearing.

Symptoms of sensorineural hearing loss

There are multiple indications of undiagnosed conditions concerning the middle and outer ear that may extend beyond simply missing a word in a conversation.

Dizziness

Dizziness can be used to describe a multitude of sensations, not simply a loss of balance. Feelings of imbalance, weakness, or being unsteady on one’s feet are all signs of Trusted SourceDizziness is a term used to describe a range of sensationsDizziness Go to source dizziness, along with the more recognizable sense that your surroundings are spinning or moving (vertigo).

Dizziness is often a symptom of undiagnosed problems concerning the ear, including Meniere’s disease, infection, and various other conditions that are treatable or correctible by a medical professional. Learn more about balance disorders caused by hearing loss.

Full, stuffy sensation or pressure

Plugged ears are often a symptom of another issue, such as inflammation or an infection. If addressed and resolved, a patient’s hearing might be fully restored. However, while this can be resolved with medication, if noise-induced hearing loss has occurred, the damage is permanent and will require hearing aids to recover lost hearing.

Difficulty understanding speech and language

Adults experiencing SNHL might miss certain words and sounds in speech, making it difficult to hear and comprehend when they are being spoken to. This might result in using subtitles during movies, or asking for someone to repeat a phrase in conversation.

In young children, undiagnosed hearing loss can also result in difficulty understanding language. Because of their age, SNHL in children can impact Trusted SourceTexas A&M University Veterinary Medical Teaching HospitalDevelopment and communication skillsGo to source development and communication skills.

Muffled hearing

Because of build-up in the ear or issues related to the eardrum, muffled hearing can be an indication of hearing loss. As the name suggests, muffled hearing may sound like you have earplugs or earbuds in.

This feeling may also be accompanied by a full or stuffy feeling in the ear.

Overall loss of hearing

Whether it’s sudden or gradual, the overall and noticeable loss of hearing can indicate sensorineural hearing loss. For patients with conditions or who take medications that can result in hearing loss, it’s especially important to watch for a gradual loss in hearing.

Tinnitus

Ringing in the ears can also be an indication of hearing loss or overall problems with the outer and middle ears. This condition isn’t simply ringing, either. Tinnitus can also sound like buzzing, whistling, roaring, and clicking.

Essentially, any sound that doesn’t have an external source or internal explanation can be considered tinnitus.

If a sound can be explained by a neurological, psychological, or medical condition, then it is considered an Trusted SourceTinnitus and Auditory HallucinationsHeard But Not SeenGo to source auditory hallucination.

Conductive hearing loss

Conductive hearing loss occurs when sound cannot travel from your outer and middle ear to the inner ear. This can either be temporary or permanent, depending on the cause, and can impact one or both ears.

Causes of conductive hearing loss

From accidents to inherited conditions, there are numerous ways that conductive hearing loss can occur. Causes can be somewhat clustered by the part of the ear, although some conditions, like microtia, which is the malformation or underdevelopment of the ear present from birth, and infections (either otitis externa or Trusted SourceTexas A&M University Veterinary Medical Teaching HospitalVeterinary school.Go to source otitis media) can impact both the outer and middle ear.

With the outer ear, causes can include:

• Cerumen impaction. The medical term for hardened, built-up ear wax, cerumen impaction occurs when patients use q-tips and other objects to clean their ears.
• Growths. This includes tumors in the ear canal, as well as bony growths, and is also known as surfer’s ear.
• Foreign objects. This might include insects, or children putting small toys in the ear.

The middle ear is less impacted by external forces, such as foreign objects, but other conditions can lead to conductive hearing loss.

• Trauma. Ruptured eardrums (tympanic membrane perforation) or Trusted SourceTexas A&M University Veterinary Medical Teaching HospitalVeterinary school.Go to source ossicular dislocation, which is when the tiny bones in the middle ear shift, can happen fairly easily.
• Otosclerosis. This is an inherited disease involving the bone that surrounds the inner ear.
• Eustachian tube dysfunction. The eustachian tube connects the middle ear and the back of the nose. Blockages in that tube can cause conductive hearing loss.
• Fluid. Occasionally, fluid can become stuck in the middle ear. This can interfere with how sound travels through the ear.
• Cholesteatoma. This is a skin cyst that is made of skin cells and debris. It can develop in the middle ear.

Symptoms of conductive hearing loss

Many of the symptoms of conductive hearing loss are the same as sensorineural hearing loss.

Difficulty hearing certain sounds, muffled hearing, and a feeling of fullness are all common with certain causes of hearing loss. Nevertheless, there are a few symptoms of conductive hearing loss that are unique.

Drainage

With a ruptured eardrum in particular, drainage can occur as fluid escapes the middle ear. It may be clear, contain puss, or be bloody depending on the cause and condition inside the middle ear.

Pain

Pressure and inflammation may lead to pain inside the ear.

In the case of a sudden decrease of pain, this could indicate that the eardrum just ruptured, releasing a buildup of pressure inside the middle ear.

Treatment for conductive hearing loss

Treatment for conductive hearing loss will depend on the cause. Because there are many causes for this type of hearing loss, it’s important to first speak with a doctor or audiologist.

Treatments might include any or all of the following options.

Hearing aids. Depending on the severity, cause, and diagnosis, an audiologist may fit you for a hearing or recommend that you shop for one.

Surgery. Surgery may be an option if the issue is correctible, such as with deformities, or severe ruptured eardrums that require a Trusted SourceRuptured eardrum (perforated eardrum)Ruptured EardrumGo to source tympanoplasty.

Observation. For conditions that should heal on their own or with medication, treatment may merely include observation by the patient and follow-up visits with an audiologist.

Treatment for sensorineural hearing loss

Treatment for SNHL will vary depending on the cause, but it should always start with visiting an otorhinolaryngologist (ear, nose, and throat doctor). Because SNHL can be caused by other issues, treatment may involve medications for the primary cause.

However, for other situations, like age-related hearing loss, treatment may be an ongoing process involving regular monitoring and the use of a hearing aid.

Here are other changes that some patients might expect, depending on the diagnosis:

Medication. Either used to treat inflammation, fluid build-up, or to treat conditions responsible for hearing loss, medications may be used to restore or improve hearing.

Lifestyle changes. Depending on the diagnosis, certain dietary changes or accessibility accommodations may be necessary to make hearing easier for the patient.

Surgery. Certain surgical procedures may correct the problem depending on if it’s caused by a structural abnormality, acoustic neuroma, or other issues within the middle or outer ear.

Hearing aids. If the problem cannot be corrected, patients can explore hearing aid options, be fitted for the appropriate hearing aid, and try different hearing aids for improved hearing.

Implants. Cochlear implants, middle ear implants, or conduction implants may be an option for some patients as well.

Mixed hearing loss

Mixed hearing loss occurs when patients experience both sensorineural and conductive hearing loss. It isn’t uncommon for patients to experience both at once or for one to develop after the other.

For example, landscapers that are frequently around loud noises, like a leaf blower, may experience sensorineural hearing loss.

Because of seasonal allergies or a cold, they may also experience a build-up in the middle ear, and, thus, conductive hearing loss at the same time.

Auditory Neuropathy Spectrum disorder

Called ANSD, this disorder is a type of sensorineural hearing loss that occurs when the cochlea, or inner ear, doesn’t transmit sound properly through the nerve to the brain. It is a spectrum disorder because it is different for each person who experiences it.

Different types of hearing tests administered in childhood can help determine if a child has ANSD early on.

Certain prenatal and postnatal indicators, like premature births and jaundice, can also heighten the risk of a child having ANSD.

Degrees of hearing loss

Hearing loss is determined on a range and measured by decibels, which is the sound pressure. Louder sounds have a higher pressure, or decibel (dB).

Frequency is the pitch of a sound, like a baritone or a soprano singer. Frequency is measured in hertz (Hz). With the auditory system and hearing loss, one or both ears may be impacted.

In addition to knowing what a decibel or hertz is, there are a few other terms that you should know.

• Unilateral hearing loss. Hearing loss is only present in one ear.
• Bilateral hearing loss. Hearing loss is present in both ears.

Here are the levels of hearing loss that patients may experience and examples of the ways in which the hearing loss can impact perceptions of sounds.

There are numerous causes of hearing loss, many of which are treatable or preventable. Because hearing loss can be gradual, patients should dedicate time to self-evaluating their own hearing and speaking to an audiologist about any concerns they may have about hearing loss and other signs of poor hearing health.