A concussion, medically classified as a mild traumatic brain injury (mTBI), can cause ringing in the ears. This symptom, known clinically as tinnitus, is the perception of sound when no external sound is present. Tinnitus is a common complaint following a head injury, with a significant percentage of individuals reporting it after a traumatic event. The sound is typically described as a buzzing, hissing, or persistent ringing, and it can be a temporary or prolonged consequence of the trauma to the head and brain.
How Head Trauma Affects Hearing Pathways
The mechanical forces involved in a concussion create a shockwave that affects the delicate structures within the head, leading to hearing disturbances through two primary routes. One pathway involves direct physical trauma to the inner ear, referred to as a labyrinthine concussion. The jarring motion can cause the membranous and bony parts of the inner ear to collide, potentially damaging the sensory hair cells within the cochlea.
These microscopic hair cells convert sound vibrations into electrical signals that travel to the brain. Damage to these cells can disrupt the auditory nerve’s signal transmission, leading to sensorineural hearing loss and the creation of phantom sounds. This localized damage explains why some individuals experience an immediate onset of tinnitus following the impact.
The second, more complex, mechanism involves the disruption of the central auditory pathways in the brain. Rotational forces during the injury can cause functional changes in the brainstem or the temporal lobe, where sound signals are processed. When the brain loses its normal auditory input, the central processing centers can become hyper-excitable.
This state of heightened activity means the brain generates its own sound signals in an attempt to compensate for the missing information. This abnormal neural activity is interpreted by the brain as the perception of ringing, buzzing, or other sounds. This central mechanism explains why the resulting tinnitus can be persistent and severe, even if the inner ear damage is minor.
Identifying Post-Concussion Tinnitus and Related Symptoms
Post-concussion tinnitus is most frequently categorized as subjective tinnitus, meaning the sound is only audible to the person experiencing it. The sound is commonly described as a high-pitched tone, though it can also manifest as a low-pitched humming, buzzing, or whooshing sound. Unlike some other forms of tinnitus, the post-concussion type is non-pulsatile, meaning it does not beat in rhythm with the heart. The presence of other symptoms related to the traumatic brain injury helps confirm the connection between the concussion and the auditory disturbance.
A common co-occurring symptom is hyperacusis, an abnormal sensitivity to normal environmental sounds. This heightened sensitivity can make everyday noises, like conversation or traffic, seem uncomfortably loud or painful.
Tinnitus frequently appears alongside vestibular symptoms, which are related to balance and spatial orientation. These can include vertigo, a sensation of spinning, or general dizziness and unsteadiness. The auditory and balance systems are located close together in the inner ear, meaning an injury often affects both simultaneously.
Many individuals experience cognitive fog, which includes difficulty concentrating, memory problems, or a feeling of being mentally slowed down. The simultaneous occurrence of tinnitus, sound sensitivity, and these cognitive challenges suggests that the symptoms are part of the broader recovery from the concussion. If an individual experiences any combination of these symptoms following a head injury, a professional evaluation is important to assess the extent of the trauma.
Management Strategies and Expected Recovery Timeline
For most people, post-concussion tinnitus is a temporary symptom that resolves as the brain and inner ear recover from the trauma. The auditory symptoms typically improve within the same timeframe as other concussion symptoms, often within a few weeks to a couple of months. Natural healing is the primary factor in the resolution of the sound.
In some cases, however, the tinnitus can become persistent, lasting longer than three months; this is often considered part of Post-Concussion Syndrome (PCS). While most people recover fully, a minority may experience symptoms that linger for six months or longer, requiring a shift in focus from curative measures to management. Even in these prolonged cases, recovery is the expected outcome.
Management strategies focus on reducing the perception of the sound and helping the individual habituate to its presence. Sound therapy is a widely used approach that involves introducing low-level external noise, such as white noise or nature sounds, to reduce the contrast between the environment and the internal ringing. This masking effect makes the tinnitus less noticeable, particularly in quiet settings or during sleep.
Cognitive Behavioral Therapy (CBT) is recommended to help manage the emotional distress and anxiety that tinnitus can cause. CBT techniques reframe the individual’s reaction to the sound, helping the brain filter out the tinnitus as a non-important signal. General concussion recovery protocols, including physical and cognitive rest, also play a role, as fatigue and stress can exacerbate the perception of tinnitus.