What is Mixed Hearing Loss? Symptoms, Causes, Diagnosis

senior man sitting on the couch and holding his ear to hear better

Hearing professionals classify hearing loss into two broad categories—conductive and sensorineural—and people sometimes experience both simultaneously. That’s called mixed hearing loss. This guide will tell you all about the causes, symptoms and treatment of mixed hearing loss.

What Is Mixed Hearing Loss?

Conductive and sensorineural hearing loss are caused by damage, disorders and deformities in different parts of the ear. Mixed hearing loss happens when there are problems in the outer, middle and inner ears all at once.

Since mixed hearing loss is a combination of the two main types, we should go over them briefly.

Conductive Hearing Loss

Conductive hearing loss refers to a breakdown in the conductive component of the auditory system. In other words, conductive hearing loss occurs when something blocks or interferes with sound on the first leg of the journey from the outer ear to the inner ear.

Conductive hearing loss signifies an issue in the outer or middle ear.

Many types of conductive hearing loss, such as earwax impactions and ear infections, are reversible.

If impacted ear wax is left untreated in the canal for too long, it can potentially lead to permanent hearing loss.

Sensorineural Hearing Loss

Sensorineural hearing loss is caused by damage to the sensorineural component of your hearing system, including highly sensitive parts of the inner ear like the delicate hair cells of the cochlea or the auditory nerve.

Sensorineural hearing loss is the most common form of hearing loss, and it is usually permanent.

What Are The Causes Of Mixed Hearing Loss?

Mixed hearing loss usually occurs when a person has one form of irreversible hearing loss and develops another. In other instances, sudden trauma or a disorder might cause both types of hearing loss at the same time. Let’s look at some causes of mixed hearing loss.

Physical Injury

Mixed hearing loss can result from accidents, violence, and head trauma.

For example, a person who stands near an explosion might experience conductive damage to the outer or middle ear from the physical impact of the blast as well as harm to the inner ear from the force and loud noise.

Genetic Conditions

Mixed hearing loss is a symptom of several genetic conditions, including branchiootorenal syndrome, which causes renal abnormalities, fistulas, and ear conditions. CHARGE syndrome causes congenital abnormalities of various body parts, including the ear.

Infections

Recurring ear infections like chronic suppurative otitis media affect the entire hearing pathway from the outer ear to the inner ear, leading to mixed hearing loss.

Progressive Hearing Loss

Mixed hearing loss often occurs when a person with permanent sensorineural hearing loss develops temporary conductive hearing loss. For example, a person might wear hearing aids to help with age-related hearing loss, and wearing dirty hearing aids could cause them to develop a blockage or middle ear infection of the ear canal.

Alternatively, someone could have a primary condition that causes chronic conductive hearing loss and then develop age-related hearing loss as they get older.

Wearing dirty hearing aids could lead to a blockage or middle ear infection of the ear canal.

Other Causes

Various other neurological and cardiovascular conditions can cause mixed hearing loss, including:

  • Demyelinating nerve conditions like multiple sclerosis that degrade the auditory nerve  
  • Neurofibromatosis
  • Cholesteatoma
  • Dehiscent carotid artery
  • Herniation of the brain and meninges

Mixed Hearing Loss Symptoms

Since mixed hearing loss is a combination of the other types of hearing loss, many of the warning signs are identical, including:

  • Inability to hear people talking and understand conversations
  • Playing TV or music at a louder volume
  • Balance problems or dizziness
  • Inner ear pain
  • Outer ear tenderness
  • Facial paralysis
  • Discharge of fluids from the ear
  • Ears feel clogged or full

It’s almost impossible to distinguish mixed hearing loss from conductive or sensorineural hearing loss based on symptoms alone. Only a hearing test can definitively diagnose this condition.

Mixed Hearing Loss Diagnosis

Diagnosing mixed hearing loss usually involves two steps. First, you’ll see your primary care provider. After a quick checkup, they’ll decide if you need to see a specialist to get your hearing tested and be fitted for hearing aids.

Initial Examination

When you see the doctor, they’ll go through a few diagnostic steps, including:

  • A review of your medical history and medications to rule out allergies, disorders and toxic reactions
  • A complete medical examination of your ears, eyes, nerves, and movements to screen for an underlying cause
  • An inspection of the ear canal with an otoscope to look for physical obstructions and check the integrity of your eardrum

If the doctor determines your hearing loss can be treated medically, they might prescribe antibiotics or cerumenolytics to deal with infection or blockage. If they suspect something more severe and irreversible, they’ll refer you for more testing.

Hearing Tests

Next, you’ll see an audiologist who will administer a series of tests to determine if your hearing loss is conductive, sensorineural, or mixed and if it is occurring in one ear or both. Often an audiologist will begin with a hearing test like Rinne and Weber to determine that hearing loss exists.

This is usually followed up with pure tone audiometry, which provides the audiologist with valuable information about the severity of hearing loss and which parts of the ear are to blame.  

Pure tone audiometry (PTA) is an air conduction test that determines the faintest tones a person can hear at varying pitches, or frequencies.

Other Tests

If your doctor is stumped about the cause of your hearing problems or suspects they might be signs of a serious underlying health problem, they might order imaging studies like MRI and CT scans or blood tests to rule out:

  • Tumors
  • Cancers
  • Neurological conditions
  • Systemic diseases
  • Cardiovascular conditions
  • Autoimmune disorders

Mixed Hearing Loss Treatment

There’s no one-size-fits-all approach for treating mixed hearing loss. The treatment depends on the cause.

This usually involves treating the different constituent types of hearing loss separately. If they’re rooted in a common medical condition, it’s necessary to address the underlying cause.

However, sensorineural damage is often irreversible, so your only option is to mitigate or manage your hearing loss with a hearing aid.  

Earwax Removal

If the conductive portion of your mixed hearing loss is caused by earwax, you need to flush out the ear canal to improve the middle ear’s transmission ability. This can be done at home with cerumenolytic drops or by an ear, nose and throat doctor using suction or special tools.

Hearing Aids

Hearing aids are often the only option for addressing the sensorineural portion of mixed hearing loss. You no longer have to settle for a conventional hearing aid. Customizable digital hearing aids can be programmed base on the type of hearing loss.

With a good set of hearing aids, you might not notice the difference. If you’re not suffering severe hearing loss, you should probably try hearing aids before risking surgical procedures.

Surgery

Surgery might be a good choice for some kinds of hearing loss. Some root causes of mixed hearing loss can be handled via surgery. Here are a few types of surgery that might help:

  • Removing acoustic neuromas and other growths around the auditory nerve
  • Reconstructing the eardrum or the ear canal
  • Cochlear implants

Assistive Technology

Hearing assistive devices are currently available for those with profound mixed hearing loss.

The American Disabilities Act guarantees people with hearing loss have the right to use assistive devices and hearing aids in public places.

This includes:

  • Hearing loops
  • Infrared systems
  • FM systems

Conclusion

Mixed hearing loss is a combination of conductive and sensorineural hearing loss. While the conductive aspect is often reversible, the sensorineural component usually is not. Fortunately, there are treatment options that can help you reduce the impact of mixed hearing loss on your daily life, including hearing aids and surgery.

If you suspect you may be developing hearing loss, contact your doctor right away.

Citations

1. Djalilian, Hamid R. MD Clinical Consultation, The Hearing Journal: November 2013 – Volume 66 – Issue 11 – p 10,12,14 doi: 10.1097/01.HJ.0000438001.09399.61