Hearing loss isn’t always caused by exposure to loud noise or old age. Sometimes an infection from a virus can cause temporary or permanent hearing loss, as well as dizziness or tinnitus. All viruses are different: not all viruses have an effect on hearing health, and those that do affect it do so in various ways. Let’s investigate the intriguing connection between viral infections and hearing loss and discuss ways to protect your hearing health when you’re sick.
Understanding Hearing Loss
First, here is a quick rundown of how our hearing works: sound waves enter the outer ear and travel into the middle ear, where they are amplified and travel further into the inner ear. The cochlea in the inner ear changes sound waves into electric signals and transmits those signals to the brain via the auditory nerve to be interpreted as sound.
There are three main types of hearing loss:
- Sensorineural hearing loss occurs due to damage to the inner ear. This type of damage affects how well the ear can communicate with the brain.
- Conductive hearing loss occurs due to damage to the outer or middle ear. This type of damage affects how the ear conducts the sound information.
- Mixed hearing loss, which is a combination of both sensorineural and conductive hearing loss.
Hearing loss may be acquired, meaning it develops in adulthood, or congenital, meaning it is acquired during development in utero. Congenital hearing loss may be present at birth or develop a few months into the infant’s life, but the underlying condition that caused hearing loss occurred during pregnancy.
How Infections Can Cause Hearing Loss
Most of the time, infections cause sensorineural hearing loss. Common symptoms of a viral infection include high fever, inflammation and altered blood flow, all of which can damage the delicate cochlea. Damage to the cochlea affects the ear’s ability to communicate sound information to the brain, which can lead to sensorineural hearing loss. Some viruses also directly target the auditory nerve and may cause damage there.
What Viruses Can Cause Acquired Hearing Loss
- COVID-19. Covid can damage the inner ear and auditory nerve.
- Influenza. The flu can affect the blood supply, which is necessary to keep the cochlea functioning.
- Measles. Hearing loss is a well-known complication of measles. Prior to the measles vaccine, it accounted for 5% to 10% of profound hearing loss in the United States.
- Shingles. Shingles affects the facial nerve near your ears, which can cause ripple effects to the auditory nerve.
- Herpes. Studies suggest that the virus invades the auditory nerve.
- Human Immunodeficiency Virus (HIV). HIV infects and kills immune cells, making your body more susceptible to further infections. HIV can also cause congenital hearing loss.
- And many others, including syphilis, the common cold (adenoviruses, enteroviruses and rhinoviruses), toxoplasmosis, ZIKA virus, cerebral malaria, Epstein-Barr virus, streptococcus, Lyme disease, mumps, meningitis, Ebola virus, West Nile virus and more.
What Viruses Can Cause Congenital Hearing Loss
- Rubella. Rubella causes direct damage to the cochlea. While symptoms are mild for most adults, a pregnant woman can pass the virus to the baby, causing complications.
- Cytomegalovirus (CMV). Research suggests that CMV expresses proteins that trigger an immune response, which causes inflammation within the cochlea and subsequent hearing loss.
If you notice a sudden change in your hearing, it’s important to get your hearing checked right away. Sometimes, sudden hearing loss is your first symptom of a sickness you didn’t know you had. If you’ve been sick, your audiologist can factor that into their conclusions. Call San Diego ENT today for more information or to make an appointment.