Ear ringing, known medically as tinnitus, happens when your brain generates a sound perception without any external source. It affects somewhere between 4% and 37% of adults worldwide, depending on how strictly it’s defined, and becomes chronic when symptoms persist longer than six months. The causes range from everyday noise exposure to underlying medical conditions, but most cases trace back to one core problem: changes in how your brain processes sound after some form of damage to the inner ear.
How the Brain Creates a Phantom Sound
Your inner ear contains thousands of tiny hair cells that convert sound vibrations into electrical signals for the brain. When these cells are damaged, whether by loud noise, aging, medications, or disease, they send fewer signals along the auditory nerve. Your brain doesn’t simply accept the silence. Instead, it tries to compensate by turning up its own internal volume.
About seven days after cochlear damage occurs, neurons in the brainstem begin increasing their spontaneous firing rate. This happens because the normal balance between excitatory and inhibitory nerve signals gets disrupted. With less inhibition keeping things in check, nerve cells start firing more often and in bursts, essentially generating electrical activity that your brain interprets as sound. The brain’s auditory cortex also reorganizes itself, with the regions that lost input retuning to respond to nearby frequencies. This “over-representation” of edge frequencies, the ones right next to the damaged range, is thought to produce the specific pitch of ringing that many people hear.
In short, tinnitus is not your ear making noise. It’s your brain overcompensating for missing input. This is why the condition persists even when the original source of damage is long gone.
Hearing Loss Is the Most Common Trigger
Around 80% of people with tinnitus also have measurable hearing loss, making it the single biggest risk factor. Age-related hearing loss is especially common. As you get older, the hair cells in your inner ear gradually deteriorate, reducing the signal your brain receives. The brain responds with that same compensatory mechanism: raising central neural gain to make up for the quieter input, which produces the phantom sound.
This is why many people first notice ringing in their ears around the same time they start having trouble following conversations in noisy rooms. The two symptoms share the same underlying cause.
Noise Exposure and Damage Thresholds
Noise becomes hazardous to your hearing at 85 decibels, roughly the volume of heavy city traffic or a gas-powered lawn mower. The CDC’s recommended exposure limit is 85 decibels averaged over an eight-hour workday. Anything louder shortens the safe window quickly. Construction workers, musicians, military personnel, and factory employees face the highest occupational risk, but recreational exposure from concerts, headphones, and power tools contributes just as much over a lifetime.
A single extremely loud event, like a gunshot or explosion near your ear, can cause immediate and permanent hair cell damage. More often, though, noise-induced tinnitus develops gradually after years of moderate overexposure. The damage is cumulative, and hair cells in the human ear do not regenerate.
Medications That Can Cause Ringing
Certain drugs are known to damage the inner ear or disrupt its function. These are called ototoxic medications, and their effects can be temporary or permanent depending on the drug, the dose, and how long you take it.
- Aspirin can cause temporary tinnitus, dizziness, and nausea when taken in large doses or overdose.
- Aminoglycoside antibiotics (gentamycin, streptomycin, neomycin) carry the highest risk among antibiotics and can cause permanent hearing damage.
- Chemotherapy drugs can attack healthy cells in the inner ear along with cancer cells, leading to hearing loss and tinnitus.
- Certain diuretics used to treat high blood pressure and fluid retention are known to affect hearing.
- Antimalarial drugs like chloroquine and quinine may cause hearing loss in rare cases.
If you notice new ringing after starting a medication, that’s worth bringing up with the prescribing doctor. In some cases, switching to an alternative resolves the problem.
Jaw Problems and the Ear Connection
The temporomandibular joint (TMJ), where your jawbone meets your skull, sits right next to the cochlea. Nerve connections have been mapped directly from the jaw region toward the inner ear, which explains why jaw problems frequently produce or worsen tinnitus.
The connection runs through a structure in the brainstem called the dorsal cochlear nucleus, where sensory input from the jaw’s trigeminal nerve converges with auditory input. Specific cells in this area sit at the crossroad of both systems, receiving signals from the auditory nerve on one end and from jaw and neck nerves on the other. When jaw dysfunction sends abnormal signals into this shared processing center, it can alter auditory perception and generate or modulate tinnitus. People with this type often notice their ringing changes in pitch or volume when they clench their jaw, chew, or turn their head.
Meniere’s Disease
Meniere’s disease is an inner ear disorder that produces a distinctive combination of symptoms: episodes of vertigo lasting 20 minutes to 12 hours, hearing loss concentrated in lower frequencies, a sensation of fullness or pressure in the affected ear, and tinnitus. The ringing typically occurs on one side only and fluctuates along with the other symptoms.
What sets Meniere’s apart from other causes of tinnitus is the episodic nature. Symptoms come in attacks rather than remaining constant, and the hearing loss tends to worsen over time if untreated. It typically affects one ear, though it can eventually involve both.
Pulsatile Tinnitus: A Different Kind of Ringing
If your ear ringing pulses in rhythm with your heartbeat, that’s pulsatile tinnitus, and it has a fundamentally different set of causes. Rather than originating from nerve dysfunction, it usually comes from altered blood flow near the ear.
Arterial causes include narrowing of the carotid artery, arterial dissection, aneurysms, and abnormal connections between arteries and veins near the skull base. Venous causes involve narrowing or compression of the large veins that drain blood from the brain, particularly the transverse sinus, sigmoid sinus, or internal jugular vein. The narrowing creates turbulent blood flow that reverberates through the temporal bone to the auditory structures, producing a whooshing or thumping sound.
Pulsatile tinnitus is one of the forms that warrants prompt medical evaluation because it can sometimes point to a vascular condition that needs treatment.
Iron Deficiency and Metabolic Causes
Iron deficiency anemia, the most common form of anemia worldwide, can affect hearing through several pathways. The inner ear’s hair cells and the tissue that maintains their electrical environment (called the stria vascularis) have exceptionally high energy demands and very limited backup blood supply. When hemoglobin levels drop, these structures don’t get enough oxygen to function properly.
Iron deficiency also impairs the energy-producing machinery inside cells, increases damaging oxidative stress, and disrupts the production of neurotransmitters involved in auditory processing. On top of all that, anemia triggers cardiovascular changes like increased cardiac output and altered blood flow patterns that can produce pulsatile tinnitus on their own. Women of reproductive age face the highest risk due to menstrual losses and the increased iron demands of pregnancy.
Diabetes and other metabolic conditions that affect blood vessel health or nerve function can similarly compromise the inner ear, though the research connecting these to tinnitus is less well-established than the link with hearing loss.
When One-Sided Ringing Needs Evaluation
Most tinnitus affects both ears roughly equally and, while annoying, doesn’t signal a dangerous condition. Certain patterns, however, call for further investigation. According to guidelines from UCSF Health, the following presentations merit specialist referral and often imaging:
- Tinnitus in only one ear, especially with hearing loss that’s worse on that side
- Pulsatile tinnitus
- Tinnitus accompanied by neurological symptoms like facial weakness or numbness
- Tinnitus that other people can hear (objective tinnitus)
One-sided tinnitus with asymmetric hearing loss is typically evaluated with a contrast-enhanced MRI to rule out an acoustic neuroma, a benign tumor on the nerve connecting the inner ear to the brain. These tumors are uncommon, but they’re treatable when caught early, which is why the asymmetric pattern gets flagged for imaging rather than watchful waiting.