The COVID-19 pandemic is primarily known for its respiratory impact, but it also causes other significant symptoms. Hearing loss is one reported neurological manifestation in some individuals infected with SARS-CoV-2. Though less common than fever or cough, auditory issues warrant attention as understanding of the virus evolves.
Recognizing Auditory Symptoms
Individuals with COVID-19 may experience various auditory symptoms, including sudden sensorineural hearing loss, tinnitus, and vertigo. Sudden sensorineural hearing loss involves a rapid decrease in hearing, often in one ear, ranging from mild to profound. Tinnitus manifests as a ringing, buzzing, or hissing sound in the ears, which can be constant or intermittent. Vertigo, characterized by a sensation of spinning or dizziness, indicates balance issues. These symptoms can appear during the acute phase of infection or emerge as a post-COVID-19 complication, sometimes weeks or months later.
How COVID-19 Affects Hearing
The mechanisms by which COVID-19 impacts hearing are complex and still being researched. One proposed mechanism involves direct viral invasion of inner ear cells, such as hair cells and Schwann cells, crucial for hearing and balance. Studies show human inner ear tissue expresses the ACE2 receptor and cofactors like TMPRSS2 and FURIN, which SARS-CoV-2 uses to enter cells. This direct infection can damage the cochlea and vestibular system.
The body’s inflammatory response to the virus, often called a “cytokine storm,” may also contribute to hearing loss. Excessive release of inflammatory cytokines can damage auditory structures, including the cochlea and the auditory nerve. Additionally, COVID-19 can cause vascular issues, such as micro-clot formation. Reduced blood flow to the inner ear due to these vascular problems can deprive delicate hair cells and nerve tissues of oxygen and nutrients, leading to dysfunction or damage. An autoimmune response, where the immune system attacks inner ear tissues after viral trigger, is another hypothesized pathway for hearing impairment.
Addressing Hearing Changes
If an individual experiences new hearing changes during or after a COVID-19 infection, prompt medical evaluation is necessary. Consulting a healthcare professional, such as an ear, nose, and throat (ENT) specialist or an audiologist, is the recommended first step. These specialists can conduct audiological tests, including pure-tone audiometry and otoacoustic emissions, to assess the type and extent of hearing loss.
Treatment approaches vary depending on the specific diagnosis. For sudden sensorineural hearing loss, corticosteroids are often prescribed, as early intervention can improve outcomes. Supportive care and rehabilitation, such as sound therapy for tinnitus or vestibular rehabilitation for balance issues, may also be recommended. Monitoring for persistent symptoms and ongoing management are part of comprehensive care.