Understanding Tinnitus

If you suffer from noises in the ears or head, known as tinnitus, you are not alone. Ear and head noises are probably the most common complaints presented to hearing healthcare professionals. Seventeen percent of the general population has tinnitus to a noticeable degree with as many as 30% of those over age 65 years reporting the presence of tinnitus.

An occasional tinnitus, especially within a very quiet environment, is not at all unusual and is reported by 90 to 95% of the population even in the absence of any ear disease or hearing disorders. Tinnitus becomes a problem for some when its intensity so overrides normal environmental sounds that it invades the consciousness.

The word tinnitus has its etymological root in the Latin tinnire meaning “to jingle.” However, the patient experiencing tinnitus may describe the sound as a ringing, roaring, hissing, whistling, chirping, rustling, clicking, buzzing, or some other similar term or description. While most who have tinnitus report the presence of their tinnitus to be constant, others have reported it to be intermittent, fluctuant, or pulsating. Tinnitus may be perceived as a high or low-pitched tone, a band of noise, or as a combination of these sounds.

The perceived loudness of tinnitus may be intense enough for some to be highly debilitating. The tinnitus itself may cause or be aggravated by difficulty sleeping, fatigue, difficulty relaxing, decreased ability to concentrate, increased levels of stress, depression and irritability. The degree to which these factors are present often far exceeds expectations based on the loudness levels of tinnitus as traditionally measured. Clearly the negative effects of tinnitus arise from more than the intensity alone.

The good news for those with tinnitus is that something can indeed be done to help.

Underlying Pathophysiology

To understand the pathopysiology of tinnitus it is first necessary to understand how the ear itself works. As can be seen in the accompanying cross section (Figure 1), the ear is comprised of much more than the visible skin and cartilage appendage on either side of our heads. A brief overview would begin with the outer ear, which extends from the auricle (what we call the “ear”) down the ear canal to the tympanic membrane, or eardrum. The larger the auricle the more effectively this is done. This is why when we are having trouble hearing we may cup our hand behind an ear. By doing so we can gather more sound waves.

The eardrum serves as the division between the outer ear and the middle ear. The middle ear is an air filled cavity, only the size of a pea, which contains the auditory ossicles (ear bones). These bones are used in transmitting the sound energy from the vibrating eardrum to the cochlea.

The cochlea is the portion of the inner ear responsible for hearing and it is within the cochlea that the origins of tinnitus arise. Within this fluid-filled, snail-shaped, bony capsule, the mechanical energy of the vibrating ear bones changes into an electromechanical energy by triggering the microscopic sensory “hair cells.” These hair cells, so named because of their appearance, send neural impulses to the brain for interpretation. (As an aside, a separately functioning portion of the inner ear attached to the cochlea [the semi-circular canals, visible in the cross section] is responsible for the sensation of balance and acceleration.)

Figure 1: Cross-section of the human ear

The Tinnitus Problem is in the Hair Cells

The sensory receptors, known as hair cells because of their appearance under magnification), are shown in Figure 2. If you can visualize a conch shell from the beach (similar in shape to the cochlea in the human ear which houses the organ responsible for hearing) with hair cells resting on a shelf that stretches throughout the coil of the shell, you can appreciate how many hair cells there are. What you see in Figure 2 is a representation of a slice of the long rows of hair cells revealing three rows next to each other called the outer hair cells (because they are positioned toward the outside of the snail-shaped cochlea) and a single row of inner hair cells.

Figure 2: Cross-sectional schematic view of the single row of inner hair cells and the three rows of outer hair cells within the organ of Corti in the cochlea of the human ear.

All nerves have a random baseline of activity. The nerve receptors at the ends of your fingers are constantly “firing” and sending impulses to the brain. These random firings are filtered out as meaningless so that the brain pays them no attention. It is only when we touch something that the nerves fire in a more patterned sequence. It is the patterned neural impulses that gain attention within the brain and that are assigned meaning.

The hair cells in the cochlea of our inner ears also fire randomly. It is only when they are triggered by the patterns of sound waves that a pattern occurs in the sequence of neural firing so that the brain pays attention to it. It is an alteration in the random neural activity of the hair cells in the absence of sound that the brain interprets as tinnitus.

How does this happen? There are approximately 3,500 inner-hair cells, and it is these inner hair cells that are responsible for hearing. The outer hair cells are responsible for fine-tuning so that we hear better. The outer hair cells are much more plentiful than the inner hair cells, numbering about 12,000. These cells, to the extent possible, will enhance the weak sounds that are received to make them more audible and they will attenuate the loud sounds to make them more comfortable. The outer hair cells are more susceptible to damage from viral infections, exposure to intense sounds, and medications that can be toxic to the ear. (See Figure 3.) Our ears can sustain a diffuse 30% damage to the outer hair cells before a decrease in hearing is even evidenced on a hearing test. However, this damage can alter the random neural activity that is normally interpreted by the brain as a code of silence. Now, the random firings, occurring in the absence of an actual sound, are “heard” by the brain. Thus, tinnitus is not a sound in the true sense of the word. Rather, tinnitus is an alteration in the normal random firings of the nerve receptors of the ear.

Figure 3. Electron micrograph of a portion of the spiral curve of the human cochlea revealing a total obliteration of the outer hair cells and their accompanying nerve fibers following occupational noise exposure.

For Some, Tinnitus is not Consciously Heard

The alterations in the normal random firings of the hair cells are “heard” only because they are a novelty: something new. Novel sounds are always heard initially, but when they loose their novelty they leave our conscious attention. An example of this is the noise of the fan of your computer. You may have been conscious of it when your computer was new and the sound was a novelty. But as you became accustomed to it, it faded from your conscious audition. It is still there, of course; and is still heard if you think about it, as you probably are now. But otherwise it is not consciously audible.

The tinnitus heard by most people loses conscious audibility when its novelty wears off. This happens when one fails to attribute any meaning or significance to the sound. If we label the sound of the tinnitus as something negative (for example, a sign of impending deafness, a sound that may worsen and over-power us, an abnormality that signifies a significant pathology such as a tumor, etc.), then emotional reactions are attached to the sound. Once this happens, we become increasingly aware of this sound that otherwise would have been filtered from our consciousness. Therefore, the primary difference between people who just notice their tinnitus, and those who suffer because of it, is the negative emotional attachments they may bring to its existence. For some of these people, the tinnitus can become quite debilitating.

The good news is that tinnitus can be helped. Click on “Help! What Do I Do From Here?” to see what you can do to combat your tinnitus.

Causes of Tinnitus

Tinnitus is not a disease but rather a symptom of another underlying problem. It is estimated that 90% of the individuals free of any ear disease or active pathology experience tinnitus from time to time. A brief occurrence of tinnitus (usually not exceeding several minutes) in one or both ears on an infrequent basis is a normal phenomenon. Tinnitus becomes a problem when it enters consciousness on a constant and prolonged basis.

Studies have demonstrated that a large number of individuals have tinnitus normally but are completely unaware of it as a factor within their lives. For many, if placed within a sound-isolating chamber and left in silence with the instruction to listen for sound, tinnitus will become present. In a normal environment, with even minimal amounts of ambient noise, these individuals are not aware of the tinnitus sound.

When pathology arises in any portion of the human auditory system, tinnitus may occur as an accompanying symptom. This usually is true as the pathology itself decreases the individual’s hearing sensitivity so that the previously unheard tinnitus becomes audible.

Pathologies that may create tinnitus as a symptom may include:

Outer-ear disorders such as impacted ear wax, foreign objects lodged in the ear canal, external ear infection, or eardrum perforation.
Middle-ear disorders such as middle ear infection, a stiffening (otosclerosis) or breaking of the chain of bones in the middle ear, vascular anomalies, neuromuscular tics, middle ear tumors
Inner-ear disorders such as Menieres disease, ear toxicity to medications, hearing loss, circulatory failure, head trauma, or inner ear infection
Central nervous system disorders such as vascular malformations, tumors, syphilis, epilepsy, or concussion
Or other disorders such as anemia, carotid arteriosclerosis, cardiac murmurs, or allergy

While most pathologies resulting in a tinnitus symptom create a tinnitus that is only heard by the tinnitus sufferer (subjective tinnitus), some tinnitus sounds with a vascular or neuromuscular origin can be faintly audible to others (objective tinnitus).

Most often tinnitus is not the symptom of any overt medical condition, but rather a sign of changes within the hearing nerve receptors as discussed in the section titled Underlying Pathophysiology. Only after potential medical pathologies have been ruled out as precursors to tinnitus should treatment of the tinnitus itself be undertaken. Often, if a medical condition is found needing attention, treatment of that condition will lead to tinnitus relief.

Treatments for Tinnitus

A variety of means of combating tinnitus have been attempted over the years. Except for some local anesthetics, which cannot be used as a continuous treatment due to their side effects, there is no effective drug that alleviates tinnitus. Other treatments providing some relief for select patients include masking, surgery, electrical stimulation, biofeedback, acupuncture, TMJ treatment, and a various pharmacological agents. Some of these treatments (notably biofeedback and acupuncture), while not directly beneficial to the tinnitus itself, can be useful in reducing stress and thereby is valuable as an adjunctive treatment to any tinnitus management program.

Negative Counseling
Negative counseling is very unfortunately one of the most common approaches to tinnitus management. It is unfortunate, as the information given to the tinnitus sufferer is unfounded and untrue. Typically negative counseling comes in words such as, “Nothing can be done for tinnitus. You’ll just have to learn to live with it.” If you have received such counseling, rest assured, something can indeed be done to lessen your tinnitus significantly.

Pharmacological Agents
There has been no specific and reliable drug treatment found for tinnitus relief. The potential side effects, tolerances to medications, developed dependence and subsequent withdrawals must be considered in any attempted drug therapy aimed at tinnitus.

Surgery
If surgically correctable ear pathology is the origin of tinnitus, surgery for remediation of the pathology may alleviate the tinnitus.

Biofeedback
Biofeedback and hypnotherapy can help decrease tinnitus through the relaxation and lessened stress that may accompany or follow such treatments. While the success of these techniques used in isolation has been varied, they may have considerable value when used in conjunction with other treatment methods.

Acupuncture
Direct relief from tinnitus through acupuncture has not been demonstrated. However, its benefits as a treatment to decrease stress and anxiety may make it useful as an adjunct to other treatment methods.

Masking
Although the masking of tinnitus is not a true masking, but rather a suppression of the tinnitus, it has proven beneficial for some individuals. Maskers are used in an attempt to cover up the individual’s perception of the tinnitus with an external sound that competes with the tinnitus. Masking can be attempted through the use of head-worn noise generators or commercial recordings of various sounds (often ocean waves, light rainfall, or waterfalls). The potential benefits of the actual suppression that may take place may be augmented by the enhanced relaxation such sounds may engender.

Hearing Aids
Many tinnitus suffers have a coexisting hearing loss of some degree. Sometimes the loss of hearing is not sufficient to create problems with communication but is sufficient in degree to reduce the natural effects of environmental sounds on the reduction of tinnitus perception. Through the use of hearing aid amplification, many tinnitus sufferers find tinnitus relief during the hours of hearing aid use. Hearing aids are possibly the most common first-line treatment method for tinnitus relief.
Tinnitus Retraining Therapy
Tinnitus Retraining Therapy (TRT) involves several counseling sessions, the use of external sound, and frequently the use of sound devices. TRT involves a retraining of the subconscious parts of the brain to ignore the sound of tinnitus and to achieve a stage in which one is not aware of, or annoyed by, the tinnitus. There are no side effects to TRT. TRT can take up to 12– 24 months to reach completion; however, for those who carefully follow the protocol, improvement should be seen within half a year.

A Homework Assignment

Something You Can Do Right Now!

There are several things you CAN do and several that you SHOULD NOT do when you are trying to alleviate some of the aggravation of tinnitus. As discussed under Help! What Can I Do From Here?, you should have a medical evaluation to rule out possible underlying medical contributors to your tinnitus. For the immediate present the following may be helpful.

Avoid exposure to loud sounds and noises. It is well documented that exposure to intense sounds can often be the underlying cause of tinnitus as well as an aggravator to current tinnitus. If you cannot avoid loud sounds, protect your hearing with earplugs or noise dampening muffs. These protectors are available through your hearing care professional as well as in the power tool section of many hardware stores and at hunting goods stores.
Caffeine (from coffee, soft drinks, chocolate, tea) and nicotine can aggravate tinnitus for many people. Try to cut back on these stimulants as much as possible. Keep in mind that if you smoke, quitting may increase your stress level which will increase the aggravation of your tinnitus until the nicotine is completely free of your system.
Improve your blood circulation through daily exercise and a decrease in your salt intake. If you have not exercised in the past consult with your physician before engaging in strenuous physical activity.
Stress can aggravate tinnitus. To the extent possible, avoid those things that add stress to your life. Learn techniques of relaxation and use them when you feel stressed.
Fatigue can increase the perception of and the aggravation of tinnitus. Be sure you are receiving adequate rest.
Avoid times of total silence. The presence of some sound in the background reduces the contrast between the level of your tinnitus and the silence of your environment. Just as a candle in a well-lit room does not appear as bright as it does in the dark, your tinnitus will appear softer, and less annoying, when you avoid silence.
Do not monitor your tinnitus. Keeping your tinnitus foremost in your mind creates higher levels of aggravation, which in turn increases the perception of the intensity of your tinnitus, which in turn brings it to a higher state within your conscious thought. You must work hard to break this cycle. It is not easy, but it can be done. Try not to think about your tinnitus. If asked about your tinnitus, respond and change the subject. Don’t talk about it with others. Work to put other thoughts in your mind. Just as you can choose not to “listen” to the sound of the fan from your computer or the voices from the TV in the other room, you can choose not to “listen” to your tinnitus. It is not easy, but with practice you will find that you are paying less attention to it.
Think positive statements only. Do not think, “Why me?” Rather think, “I am doing something positive for my tinnitus. It’s going to get better!”
HELP! What Do I Do From Here?

The first, and vital step in attaining tinnitus relief is determining that there is no pathological condition underlying the symptom of your tinnitus. A good starting point is with your physician. A variety of medical conditions can be at the root cause of tinnitus including hypertension, high cholesterol, thyroid abnormalities, anemia, diabetes and a variety of prescription and non-prescription medications. Consultation with your physician should aim at ruling out or attending to these potential contributors to tinnitus.

If following consultation with your physician, no immediate causes are identified for your tinnitus, you should schedule an audiologic and otologic evaluation to identify any ear specific pathologies that may be present. Following any audiologic (hearing) evaluation, if no ear disorders are identified other than a possible cochlear hearing loss (at the level of the hair cells as discussed under pathophysiology of tinnitus), the audiologist may conduct a tinnitus interview to determine the characteristics of your tinnitus and its effects on your life style. At that point, appropriate recommendations can be given for the management of your tinnitus.

American Academy of Audiology

Position Statement on Tinnitus

Audiologic Guidelines for the Diagnosis & Management of Tinnitus Patients
Tinnitus refers to an auditory perception not produced by an external sound. It is commonly described as a "hissing, roaring, or ringing" and can range from high pitch to low pitch, consist of multiple tones, or sound like noise (having no tonal quality at all). It most often is constant, but can also be perceived as pulsed, or intermittent, and may begin suddenly, or may come on gradually. It can be sensed in one ear, both ears, or in the head. It has been estimated that as many as 40-50 million U.S. residents have experienced more than momentary tinnitus with as many as 2.5 million reporting feeling debilitated by the symptom. As many as 10-12 million individuals have sought help for the condition. Tinnitus may cause or be associated with a wide range of problems including sleep difficulties, fatigue, stress, trouble relaxing, difficulty concentrating, depression, and irritability. As a result it can affect one's quality of life including social interactions and work.

Scope of Practice
Audiologists are qualified to evaluate, diagnose, develop management strategies, and provide treatment and rehabilitation for tinnitus patients. In evaluating and managing tinnitus, it is helpful and worthwhile for audiologists to work with a multidisciplinary team approach.

Suggested Evaluation Guidelines
Prior to recommending or beginning any treatment for tinnitus, it is essential that a differential diagnosis be attempted. It is important to consider the entire person, not merely the audiogram and/or the characteristics of the tinnitus. There are many factors that can cause and affect tinnitus and its perception that will influence the management plan and outcome of any treatment.
- Comprehensive case history including, but not limited to, questions regarding time of onset, course of progression, description, location, perceived cause, extent to which the patient is bothered, exacerbating factors (such as food, stress, lack of sleep, etc.), history of noise exposure, medications, familial history of hearing loss or tinnitus, effect on sleep, and effect on personal/social/occupational relationships.
- Loudness discomfort levels
- Tinnitus pitch matching
- Tinnitus loudness matching
- Minimal masking level
- Subjective questionnaires; There are several valid and reliable surveys designed to measure the disability and handicap associated with tinnitus.
Professionals that specialize in the assessment and treatment of tinnitus also may find additional audiologic procedures useful for diagnosis and counseling.
Tinnitus Patient Management Procedures Similar to the evaluation process, the treatment of patients with tinnitus is most likely to succeed when a multidisciplinary approach is employed. While it is true that at this time there is no cure for most cases of tinnitus, it is not true that "there is nothing that can be done about it". A number of treatment approaches that can be performed by audiologists have been described with various degrees of reported success. They are listed below (in alphabetical order) along with a brief description:
- Counseling: A trained professional counselor can be very helpful whenever the tinnitus becomes problematic. Counseling should be considered both as a primary approach, when appropriate, and as an adjunctive approach, to all treatment strategies. Counseling consists of gathering data through careful listening, making adjustments in one's strategies based on that knowledge, and conveying information. Thus, it serves both a diagnostic and therapeutic function.
- Cognitive Behavioral Therapy One type of counseling that may be successful in helping people cope with tinnitus is cognitive behavioral modification therapy. This approach can help persons identify the way they react to their tinnitus and learn new responses, thereby minimizing the negative thoughts and behavior patterns that are associated with tinnitus.
- Habituation and Tinnitus Retraining Therapy Tinnitus Retraining Therapy is a method developed to facilitate habituation to tinnitus. It combines sound enrichment therapy with directive counseling. Sound is employed to reduce the contrast between silence or ambient noise and the perception of the tinnitus. It may be in the form of environmental sounds, amplification, or broadband sound generating devices. A reduction of the perception of the tinnitus (but not complete obliteration of it) is considered essential to the process of habituation. Counseling and education serve to demystify tinnitus, providing the patient with an intellectual and emotional framework in which habituation can occur.
- Hearing aids and tinnitus instruments For individuals with hearing loss, environmental sounds may be inadequate in themselves to afford relief. However, amplifying them with the assistance of hearing aids may provide enough background stimuli to give tinnitus relief, while simultaneously enhancing the individual's listening and communication abilities. If hearing aids alone are inadequate, tinnitus instruments may be of help. Tinnitus instruments are devices that provide amplification, and add the option of an independently controlled broadband sound generator.
- Maskers & home masking devices Maskers are used to cover-up the tinnitus perception with a competitive signal that either partially or completely competes with or conceals the tinnitus. This can be achieved by a number of methods, ranging from environmental masking to ear-level worn sound generators. Also, there are commercially available recordings of a wide range of sounds that can provide complete or partial masking. In addition to their masking effect, these sounds may assist in relaxation.
- Self-help and Support/Education Groups Some people find help, stay informed on the latest information, and share treatment experiences by talking to others with similar problems. These groups should be facilitated, or at least attended, by an audiologist or a psychologist (to prevent misinformation from being conveyed) and may include lectures from a variety of related disciplines.
- Stress Management Stress can aggravate tinnitus, and tinnitus can be very stressful. There are many procedures that can be helpful in learning to manage stress. Biofeedback assisted relaxation is one technique that people can learn to control breathing, muscle tension and heart rate. Other methods of stress reduction include yoga, meditation, self-hypnosis, and exercise.
- There is no evidence to support the effectiveness of alternative treatments such as acupuncture, homeopathy, and herbal remedies such as ginkgo biloba.