Study Links COVID-19 History to Worse Hearing Thresholds

A Brazilian study of 240 adults found that people with a confirmed history of COVID-19 had higher hearing thresholds and more than twice the odds of measurable hearing changes compared with unexposed peers.

Since the early years of the pandemic, researchers have catalogued the ways COVID-19 can linger in the body, from fatigue and brain fog to changes in smell and taste. Whether the virus also leaves a mark on hearing has remained an open question, with studies pointing in different directions and many relying on self-report rather than formal audiometric testing.

A new cross-sectional study from Brazil, published in International Archives of Otorhinolaryngology, takes the more rigorous route. Researchers measured pure-tone hearing thresholds in 120 people with a confirmed history of COVID-19 and 120 people without, then compared the two groups ear by ear.

Background: Why the Researchers Looked at This

Viral infections have long been recognized as a potential cause of hearing damage. Measles, mumps, and cytomegalovirus can all injure the inner ear, so it was natural for audiologists to ask early on whether SARS-CoV-2 might do the same, whether through direct effects on the ear, inflammation, or changes in blood supply to the delicate structures of the cochlea.

The evidence so far has been mixed, and the authors describe real uncertainty about whether COVID-19 is a risk factor for hearing loss. Many earlier reports were small, lacked control groups, or leaned on patients noticing symptoms themselves, which is unreliable because gradual or high-frequency hearing changes often go unnoticed in daily life.

This study was designed to address those weaknesses with formal pure-tone audiometry, the standard clinical test in which listeners respond to faint tones across different pitches, in a reasonably large group of exposed and unexposed adults.

How the Study Was Done

The researchers evaluated 240 adults between 2021 and 2023. Half had a confirmed history of COVID-19 infection; half had no known exposure. Each participant underwent pure-tone audiometry, and the resulting hearing thresholds, the quietest sounds a person can reliably detect at each frequency, were compared between groups for both ears.

Participants in the exposed group also reported which ear, nose, and throat symptoms they had experienced during their illness. This let the team test whether any particular symptom during infection was associated with measurable changes on the hearing test afterward.

What the Researchers Found

The group with a history of COVID-19 showed predominantly higher median tonal thresholds than the unexposed group in both ears, meaning they needed sounds to be louder before they could hear them. Altered hearing thresholds were found in 28.3% of exposed individuals versus 15% of unexposed individuals, which works out to an odds ratio of 2.24 (95% confidence interval: 1.18 to 4.25).

Comparing each person's right and left ears revealed another pattern: the hearing impairment in the exposed group was often asymmetric, affecting one ear more than the other.

Among symptoms reported during the illness, nasal complaints (67.5%), cough (65.8%), and loss of smell (60%) were most common. Hearing-related symptoms were less frequent: tinnitus was reported by 19.2%, earache by 18.3%, and hearing loss by 18.3%. Crucially, only two symptoms were statistically associated with measurable threshold changes: self-reported hearing loss (odds ratio 8.9) and tinnitus (odds ratio 3.7).

Notice the gap in those numbers. While 28.3% of exposed participants had measurable hearing changes, only 18.3% had reported hearing loss as a symptom. Some people carried audiometric changes they apparently had not noticed or attributed to the illness.

What It Means for People with Hearing Loss

For the many adults who have had COVID-19, this study is not cause for alarm: most exposed participants had normal thresholds. But it does strengthen the case that the infection is associated with worse hearing on formal testing, and that noticing tinnitus or hearing difficulty during or after the illness is a meaningful signal worth acting on rather than dismissing.

The broader lesson is about detection. Hearing changes, whatever their cause, frequently escape notice because they arrive gradually or affect one ear or certain pitches more than others. A formal hearing check is the only reliable way to know where you stand, especially after a significant illness.

When Hearing Changes Slip By Unnoticed

One of the quieter findings here is that measurable hearing changes outnumbered the people who actually reported hearing loss. That gap between what audiometry detects and what people notice is a recurring theme in hearing research, and it is one reason many adults wait years before addressing mild to moderate hearing loss.

Newer FDA-OTC hearing aids are designed to lower the barriers, in cost and in convenience, that keep people from acting on those changes. Panda Air is one such device: a modern earbud-style hearing aid with 16-channel processing, multi-band adaptive noise reduction, a fast-charge case providing 60 hours of total use, and Bluetooth for calls, TV, and music. As a self-fitting OTC hearing aid, it offers an optional app-based in-ear hearing test that measures your responses across frequencies through the aid itself and personalizes gain and frequency response to your hearing profile. The app and test are entirely optional, and Air works out of the box without them.

Air carries a 5-year warranty and a 45-day trial that begins when the product arrives. One caveat worth repeating: OTC hearing aids are approved for mild to moderate hearing loss, and severe or profound loss still benefits most from a clinical fitting. Learn more about Panda Air here.

Limitations of This Research

This was a cross-sectional study, meaning hearing was measured at a single point after infection rather than before and after. Without pre-infection audiograms, the study cannot prove that COVID-19 caused the observed differences; the groups could have differed in other ways, such as noise exposure history or unrecorded health conditions. Symptom reports also depended on participants' recall of an illness that may have occurred well before testing.

The study was conducted at a single center in Brazil, and details such as infection severity, vaccination status, and viral variant were not broken out in the abstract available through PubMed. Funding sources and potential conflicts of interest were likewise not detailed there.

What to Do With This

The practical takeaway is simple. If you noticed tinnitus or hearing difficulty during or after a COVID-19 infection, those symptoms carried the strongest association with measurable hearing changes in this study, so a formal hearing evaluation is a sensible next step. And even without symptoms, an occasional hearing check is a low-effort habit, because this research is a reminder that our ears do not always tell us when something has shifted.

Castoldi MA, Ribeiro FAQ. Audiometric Profile in Post-COVID-19 Patients. International Archives of Otorhinolaryngology. 2026. Retrieved from PubMed. https://doi.org/10.1055/a-2873-4569