A person with tinnitus hears the sensation of a sound even in silence. Often described as ringing in the ears, the sound may resemble a buzzing, roaring, hissing, swooshing or clicking. Sometimes the phantom sound is low-pitched, high-pitched, soft or loud, and it may occur in one or both ears. It may be temporary (acute) or ongoing (chronic).
Nearly 50 million Americans, or 15 percent of the population, experience tinnitus, while 2 million people have a debilitating case of it, making it difficult to work or sleep, according to the U.S. Centers for Disease Control.
While anyone can get tinnitus, most cases are found among senior citizens; people employed in loud workplaces; musicians and music lovers; motorsports and hunting enthusiasts; and military personnel. Tinnitus is the most common disability among U.S. military veterans. Tinnitus is increasing amongst young people who expose themselves to loud sounds.
What Causes Tinnitus?
Tinnitus isn’t a disease but a reaction in the brain to changes in the ear, often caused by noise overexposure. The central auditory system or auditory part of the brain undergoes molecular and physiological changes in response to reduced auditory nerve input, which result in the phantom perception. Other areas of the brain including other senses and attention and emotion centers can also be altered.
While the most common factor associated with tinnitus is noise overexposure, there are other associated factors including:
- Middle ear obstructions
- Ear and sinus infections
- TMJ disorders
- Blood vessel or heart disorders
- Ménière’s disease
- Brain or neck tumors
- Hormonal changes in women
- Thyroid problems
- Certain medications
- Alcohol, aspirin and caffeine
Researchers believe the source of the ringing is not found in the ear but rather in brain cells that communicate with each other, called the neural circuits. The neural circuits are affected by changes in the ear.
Diagnosis of Tinnitus
If tinnitus is suspected, an otolaryngologist (an ear, nose, and throat doctor, or an ENT) may order the following tests to diagnosis it:
- Audiology/audiometry to gauge hearing loss
- Specialized audiology testing which recreates and matches the exact audio of the tinnitus, masks the noise or discovers the volume at which external sound becomes painful
- Blood vessel studies (angiography)
- Head CT scan
- Head MRI scan
Treatment for Tinnitus
While there is no cure, an ENT first treats any underlying issues that may be causing tinnitus, right down to removing ear wax. Standards of treatment currently used in tinnitus clinics include:
- Use of therapeutic sounds
- Cognitive behavioral therapy
- Limiting exposure to loud noise
- Adopt a sound generator to emit low-level noise to mask symptoms
- Wear a hearing aid to increase volume of wanted sounds
- Incorporate acoustic stimulation to change neural circuits in the brain
- Undergo deep brain stimulation and vagal nerve stimulation
- Receive counseling to manage and accept tinnitus
- Avoid total silence
- Explore medications to relieve symptoms or reduce anxiety
Tinnitus Research at the University of Michigan
Kresge Hearing Research Institute, inside the Department of Otolaryngology at Michigan Medicine, is on the cutting-edge of researching mechanisms underlying tinnitus and developing novel, basic science- based treatments for patients with tinnitus through research funded by the National Institutes of Health and private foundations.
U-M has patented the concept behind a new device developed during tinnitus research. Called targeted bimodal auditory-somatosensory stimulation, this device plays a sound into the ears and delivers weak electrical pulses to the cheek or neck. Careful specification of the exact timing between the two sensory stimulations, based on neural recordings in animals are used to quiet the phantom sounds by targeting unruly neural-circuit activity. Learn more about targeted bimodal auditory-somatosensory stimulation on the Michigan Lab Blog.
The device remains experimental and is not yet commercially available. The current clinical trial is no longer accepting subjects as the recruitment pool is now complete. They expect results from the second trial in fall 2020.