Tinnitus (pronounced tih-NITE-us or TIN-ih-tus) is sound in the head with no external source. For many, it's a ringing sound, while for others, it's whistling, buzzing, chirping, hissing, humming, roaring, or even shrieking. The sound may seem to come from one ear or both, from inside the head, or from a distance. It may be constant or intermittent, steady or pulsating.
Microvascular compression may sometimes cause tinnitus. According to Levine (2006) the quality is similar to a "typewriter", and it is fully suppressed by carbamazepine. It seems to us that response to carbamazepine is not a reliable indicator of microvascular compression as this drug stabilizes nerves and lowers serum sodium. Nevertheless, this quality of tinnitus probably justifies a trial of oxcarbamazine (a less toxic version of carbamazepine).
A large, 2014 study of almost 14,000 people found obstructive sleep apnea was linked to significantly higher rates of hearing impairment and hearing loss. Scientists think one reason for this is changes to blood flow to the ear that result in inflammation. (We know that sleep apnea causes changes to circulation and weakens blood flow to some areas of the body, including the brain.) A related factor? People with sleep apnea are at greater risk for high blood pressure, and high blood pressure can exacerbate hearing loss, according to research.
Tinnitus is a common condition characterized by the perception or sensation of sound even though there is no identifiable external source for the sound. Tinnitus is often referred to as a “ringing in the ears.” However, the sounds associated with tinnitus have also been described as hissing, chirping, crickets, whooshing, or roaring sounds, amongst others, that can affect one or both ears. Tinnitus is generally broken down into two types: subjective and objective. Subjective tinnitus is very common and is defined as a sound that is audible only to the person with tinnitus. Subjective tinnitus is a purely electrochemical phenomenon and cannot be heard by an outside observer no matter how hard they try. Objective tinnitus, which is far less common, is defined as a sound that arises from an “objective” source, such as mechanical defect or a specific sound source, and can be heard by an outside observer under favorable conditions. The sounds from objective tinnitus occur somewhere within the body and reach the ears by conduction through various body tissues. Objective tinnitus is usually caused by disorders affecting the blood vessels (vascular system) or muscles (muscular system).
It is possible that the most common cause of pulsatile tinnitus is sigmoid sinus diverticulum and dehiscence, which can be collectively referred to as sinus wall abnormalities or SSWA. The sigmoid sinus is a blood carrying channel on the side of the brain that receives blood from veins within the brain. The blood eventually exits through the internal jugular vein. Sigmoid sinus diverticulum refers to the formation of small sac-like pouches (diverticula) that protrude through the wall of the sigmoid sinus into the mastoid bone behind the ear. Dehiscence refers to absence of part of the bone that surrounds the sigmoid sinus in the mastoid. It is unknown whether these conditions represent different parts of one disease process or spectrum, or whether they are two distinct conditions. These abnormalities cause pressure, blood flow, and noise changes within the sigmoid sinus, which ultimately results in pulsatile tinnitus. Narrowing of the blood vessel that leads into the sigmoid sinus, known as the transverse sinus, has also been associated with pulsatile tinnitus.
When there does not seem to be a connection with a disorder of the inner ear or auditory nerve, the tinnitus is called nonotic (i.e. not otic). In some 30% of tinnitus cases, the tinnitus is influenced by the somatosensory system, for instance people can increase or decrease their tinnitus by moving their face, head, or neck. This type is called somatic or craniocervical tinnitus, since it is only head or neck movements that have an effect.
CBT could potentially help people with tinnitus deal with fears that their tinnitus might be caused by brain damage or might lead to deafness. During CBT, they might learn that the condition is common and that it is not associated with brain damage or deafness. They might also be exposed to the sound in a safe environment, so that it has less of an impact on their daily life. CBT also involves techniques such as applied relaxation and mindfulness training.
Cochlear implants are sometimes used in people who have tinnitus along with severe hearing loss. A cochlear implant bypasses the damaged portion of the inner ear and sends electrical signals that directly stimulate the auditory nerve. The device brings in outside sounds that help mask tinnitus and stimulate change in the neural circuits. Read the NIDCD fact sheet Cochlear Implants for more information.
The treatment involves implanting a small electrode into a person’s neck near the vagus nerve. The patient then listens to specific tones that are paired with small electric pulses sent to the vagus nerve. This vagus nerve stimulation, coupled with the sound-based stimulation of the auditory cortex, can “turn down” the patient’s tinnitus. Though, Kilgard adds, “It’s not 100 percent yet.”
Tinnitus is the perception of sound when no actual external noise is present. While it is commonly referred to as “ringing in the ears,” tinnitus can manifest many different perceptions of sound, including buzzing, hissing, whistling, swooshing, and clicking. In some rare cases, tinnitus patients report hearing music. Tinnitus can be both an acute (temporary) condition or a chronic (ongoing) health malady.