Tinnitus is where there is the perception of ringing, buzzing or hissing noise in the ears despite the absence of any source of these sounds. Tinnitus is common and affects between 10 to 15% of the population. It is not a disease but a symptom of underlying conditions like ear injury, age-related hearing loss, ear infections or a circulatory system disorder. The cause however, cannot always be clearly identified in all cases of tinnitus.
Tinnitus is of two types:
- Subjective tinnitus involves perceiving noises in the absence of a stimulus. This may arise with problems in the ear structures itself, the auditory nerves (which pass signals from the ear to the brain) or the part of the brain that interprets nerve signals as sound.
- Objective tinnitus results from real noise made by structures within the ear or in the environment. It may also be audible to others around the patient.
Tinnitus is symptom and not a disease. The sound that the patient hears is typically reported to be like a constant ring, buzz, roar, click, whistle, or hiss when no external sound is present. The noises may vary in pitch and it is often disturbing to the patient. Tinnitus can affect one or both ears. In some cases, the noises can interfere with concentration and the ability to hear real sounds.
Sound generates pressure waves in the air. The human ear is developed to capture these waves (outer ear) and transmit it (middle ear) to the hearing apparatus (inner ear). The cochlear of the inner ear has tiny, delicate hairs that move in relation to this pressure. This movement is translated into an electrical signal. A nerve from the ear (auditory nerve) carries this signal to the brain where the signal is deciphered as sound.
Following are some of the conditions that affect this ‘hearing machinery’ and cause tinnitus.
- Damage to the tiny hairs inside the inner ear can cause leaking of abnormal electrical signals to the brain.
- Age-related hearing loss (presbycusis).
- Exposure to loud noises (explosions, industrial equipment, firearms, and music devices). Tinnitus caused by a short-term exposure usually goes away on its own but prolonged exposure to loud sounds can damage hearing permanently.
- Irritation of eardrum by earwax blockage
- Medical conditions :
– Abnormal pressure or composition of inner ear fluid in Meniere’s disease
– Disorders of temporomandibular joints (joint connecting lower jawbone and skull)
– Neurological disorders, head or neck injuries
– Non-cancerous tumors on the cranial nerve (nerve controlling balance and hearing)
– Stress and depression worsen tinnitus
- Ear bone changes like hardening of the middle ear bones (otosclerosis) or abnormal bone growth
- Blood vessel disorders cause pulsatile tinnitus and may result from:
– Head and neck tumors (vascular neoplasm) pressing the blood vessels
– Atherosclerosis (buildup of cholesterol) inside the blood vessels close to the middle and inner ear.
– Increased blood pressure due to hypertension, stress, consumption of alcohol and caffeine
– Narrowing or kinking of carotid artery or jugular vein
– Abnormal formation of capillaries between arteries and veins
- Some medication like certain antibiotics, anti-cancer drugs, diuretics, malaria drugs or high doses of aspirin can cause tinnitus.
Treatment of tinnitus is aimed at the underlying health condition, when it can be identified. Removing earwax, treating a blood vessel condition with medication or surgery, and changing the tinnitus-causing drugs usually addresses the problem.
Use of electronic devices (like white noise machines, hearing aids, tinnitus retrainers, and masking devices) is frequently recommended to suppress the noise.
Medications like tricyclic antidepressants (amitriptyline, nortriptyline) and alprazolam can reduce the severity of the symptoms and decrease the complications.