Hyperacusis has not been studied as long or as extensively as tinnitus. However, in many patients, tinnitus and hyperacusis coexist and are treated together. As was the case with tinnitus, no definitive cure for hyperacusis has been identified, but through counseling and various treatment approaches (e.g., desensitization therapy), this disorder can be managed successfully in many individuals. Procedures such as these can be a critical factor in restoring or establishing the ability of patients to function normally in their everyday activities despite the continued presence of aversions to many common, everyday sounds.

Auditory hallucinations are new to audiology here in the United States. Although new to audiology, this disorder has been studied by psychologists and psychiatrists for some time as many individuals with auditory hallucinations present with psychiatric conditions, such as schizophrenia. Recent research has implicated changes in the anatomy of the central auditory system associated with hallucinations and has shown that many people without comorbid diagnoses of psychological and/or psychiatric conditions also experience auditory hallucinations. These findings have stirred the interest and attention of audiologists. The elderly with histories of long-standing severe hearing loss are one group of patients who seem to be prone to auditory hallucinations. Another group that experiences auditory hallucinations includes patients with neurologic damage involving the central auditory structures. As you will read later in this chapter, the definitions of subjective tinnitus and auditory hallucinations are quite similar, with both involving the perception of sound in the absence of an external auditory stimulus.

The research surrounding tinnitus, hyperacusis, and auditory hallucinations is indeed interesting and will be pursued more in the future. Similarities as well as differences in these three hearing disorders will likely herald advances in both the understanding and treatment of these problems. However, it is important to keep in mind that not all patients who experience one or more of these “hearing” symptoms will have an auditory basis for their disorder. Some will have a nonauditory basis (e.g., a psychological or psychiatric condition), and others may have a comorbid auditory and nonauditory basis. Referrals to other professionals will be critical for those cases where psychological or psychiatric problems are suspected either as a primary cause or as a comorbid condition.

Tinnitus generally is classified into two main categories, subjective and objective. Subjective tinnitus can be heard only by the person who experiences it. It is often described as a ringing, hissing, humming, chirping (as in the sounds made by crickets and/or cicadas), whistling, blowing, or roaring sound. Objective tinnitus, on the other hand, can be measured if a probe microphone or stethoscope (even a hearing aid stethoscope) is placed in the ear canal or on the pinna. It also may be heard by others who are in close proximity to the individual if the tinnitus is loud enough to be perceived. This type of tinnitus is commonly described by sufferers as being a pulsatile, clicking, or rushing type of sound (Marion & Cevette, 1991).

Due to the likely presence of multiple pathophysiologic factors in many tinnitus sufferers, it is difficult to determine which one actually triggers the tinnitus. It may be possible that a constellation of factors needs to exist to create the perception of tinnitus. Although the previous discussion has focused on pathophysiologic alterations or compromise in the cochlea and/or the auditory nerve, it also is important to realize that involvement of the auditory pathways in the brain can additionally result in tinnitus (Lockwood, Salvi, & Burkard, 2002; Møller, 2000).

This type of finding would suggest that the central auditory pathways may be responsible for the generation and/or persistence of tinnitus in some cases. This is not to say that cochlear damage cannot cause tinnitus. It is highly likely that damage to the cochlea from insults such as high intensity noise or Ménière’s disease will result in the cochlea generating subjective tinnitus. However, a study by Lockwood et al. (2002) indicates that neural activity within the brain also can generate tinnitus (at least some of the time). Functional imaging studies have demonstrated that tinnitus activates the auditory cortex on only one side of the brain, whereas an external tonal stimulus activates both cortices. In addition, changes in functional imaging measures have been documented for individuals who can increase the loudness of their tinnitus by gazing in a certain direction or by clenching their teeth. In these cases, the changes in functional imaging measures revealed increased cortical activity that correlated with the tinnitus provoking maneuvers (see Lockwood et al., 2002, and Møller, 2000, for reviews).

An additional observation that is worth mentioning relates to what appears to be a disconnect between the apparent anatomic site of abnormality and the site of physiologic abnormality. This “disconnect” could add to the difficulty of interpreting the triggers and nature of tinnitus in many patients. Additional research is needed to delineate the nature and exact site of physiologic abnormalities in individuals for whom there may be a discrepancy between the apparent anatomic site of pathology and the actual physiologic site of abnormality.

At this point in time, it is probably best to keep an open mind and entertain the possibility that subjective tinnitus can be localized in the cochlea, the auditory nerve, and/or the central pathways. Currently, there is little in terms of test procedures that allow the accurate localization of tinnitus within the peripheral and/or central auditory system. Tinnitus often can be localized by the patient to one ear, both ears, or to an area more centrally located in the head. If localized to one or both ears, it is commonly assumed that the tinnitus arises from a peripheral auditory structure. On the other hand, it is inviting to think that tinnitus located in the head or midline may have a central origin; however, currently there is a paucity of evidence to support a precise locus of this symptom.

Following a thorough case history, a full head and neck examination is necessary. Included in this examination should be a comprehensive otologic examination, including otomicroscopy. Additionally, each cranial nerve should be examined as some otologic disorders (such as a mass lesion) may affect primarily the auditory nerve, resulting in tinnitus, but they also may affect one or more of the adjacent nerves. An examination of all of the cranial nerves can provide insight as to the basis of the underlying problem (Fortune, Haynes, & Hall, 1999). An audiologic evaluation is also warranted to determine if a hearing loss is present and to rule out significant retrocochlear involvement as a contributory factor to the symptom if a hearing loss is identified. Although nonpulsatile, bilateral tinnitus often does not require any further medical examination, individuals who present with unilateral tinnitus or pulsatile tinnitus, as well as those with asymmetric hearing loss, should be seen for a magnetic resonance imaging (MRI) with gadolinium contrast procedure (Schwaber, 2003). In particular, the internal auditory canals should be examined. For those patients who cannot undergo an MRI, an auditory brainstem response (ABR) evaluation or computed tomography (CT) scan should be considered. In addition to traditional imaging, patients with objective pulsatile tinnitus should be evaluated for a variety of disorders including neoplasms, vascular lesions, benign intracranial hypertension, great vessel bruits, and high cardiac output (Perry & Gantz, 2000). These individuals should undergo additional examinations as appropriate, which may include magnetic resonance angiography (MRA) or arteriograms. The benefit of MRA is that it is essentially noninvasive, and it is additionally helpful in determining both arterial and venous involvement. Laboratory testing also may be indicated for some patients. Patients may be evaluated for a variety of disorders, which may include endocrinopathies, metabolic disorders, autoimmune diseases, and syphilis (House & Derebery, 1995).

An audiologic, or sometimes termed psychoacoustic, assessment of tinnitus can prove valuable in a number of ways and should be included in the evaluation of the patient who presents with tinnitus. Tyler and Erlandsson (2003) mention five ways that the evaluation of tinnitus can be used. These include: (1) to confirm that the patient has tinnitus, (2) to monitor changes in the tinnitus over time, (3) to provide insights as to underlying mechanisms, (4) to help in the fitting of devices for tinnitus treatment, and (5) to render a determination of the reliability of the patient’s report of tinnitus, which may be important, especially in legal cases. Although such testing is often desirable, many patients will find tinnitus assessments to be challenging and often difficult to complete. Therefore, it is important that the audiologist’s rationale for conducting the psychoacoustic testing be well thought out and made clear to the patient. The evaluation of tinnitus is indeed difficult and not as accurate or precise as most would like it to be. This fact should be understood by those undertaking this challenging task. Despite various psychoacoustic strategies that have been invoked to complete tinnitus matching procedures in the clinical setting, the results remain quite variable as tinnitus has many components and it often changes quickly in pitch and loudness, rendering it difficult to measure.

The key aspects of tinnitus assessment center around pitch and loudness matching (see Marion & Cevette, 1991; Tyler & Erlandsson, 2003). In tinnitus matching procedures, the patient is asked to match the pitch and loudness of his or her tinnitus to external sounds presented under earphones. Multiple replications are usually required to reach stable values. In cases of unilateral tinnitus, matching can be performed with the external sound presented to the ipsilateral ear (ear with the tinnitus) or the contralateral ear (ear without the tinnitus). If bilateral tinnitus is present, each ear must be evaluated separately, which can be challenging. In addition to the matching procedure, a masking procedure can be used. In the masking procedure, the sound pressure level (SPL) of a broadband noise needed to mask out perception of the tinnitus is determined. This procedure, as well as the loudness matching procedure, can give some indication of the perceived loudness of the tinnitus. It has been reported that most people match their tinnitus to an external stimulus that is in the 10 to 30 dB sensation level (SL) range (Møller, 2000). However, a more recent study has shown that the average intensity match for tinnitus was under 10 dB SL for patients with histories of noise exposure (Nageris, Attius, & Raveh, 2010), and clinical experience has also shown that the intensity match for the majority of patients is below 10 dB SL (Vernon & Meikle, 2000). It is important to note that the measurement of tinnitus loudness is affected considerably by the frequency at which the measure is obtained. The SL values typically are lower when loudness is measured at the pitch (i.e., the frequency) of the tinnitus than when it is measured at a lower frequency (see Vernon & Meikle, 2000, for additional information on loudness matching procedures and findings).

Sometimes the frequency of the tinnitus is related to particular otologic problems. For example, the tinnitus experienced by patients with Ménière’s disease is often matched to a low-frequency stimulus and is occasionally pulsatile in nature, whereas the tinnitus experienced by patients with noise-induced loss is more commonly matched to a high-frequency stimulus (Douek & Reid, 1968). Even the more recent report from Nageris et al. (2010) reflected this trend in individuals with noise-induced hearing losses. However, from the present authors’ view, the strength of these relationships has not always been highly reliable or specific. Therefore, it is important that one does not limit testing to a particular frequency range when assessing patients, even if one anticipates a likely match within a specific frequency range based on the patient’s presenting symptoms and/or otologic diagnosis.

The masking of a patient’s tinnitus has been discussed for many years, both as a diagnostic procedure and as a management tool. In most cases, tinnitus can be effectively masked using a broadband noise stimulus. In fact, 91% of the patients in an investigation conducted by Vernon and Meikle (1988) achieved complete masking of the tinnitus. If a patient’s tinnitus can be easily masked with a broadband stimulus, it may indicate that a masking device may work well as a management option for that patient. In a large number of subjects with tinnitus, Savastano (2008) reported that slightly more than 50% of the patients had their tinnitus masked by a broadband noise in the 31 to 60 dB range, whereas slightly more than 30% required levels in excess of 60 dB (although not specified in this study, these levels were assumed to be effective masking levels and not SL measures). Savastano (2008) also related that individuals with hearing loss required higher levels of noise to mask their tinnitus than those with normal hearing (see qualifying comment offered earlier).

Residual inhibition (the time period with complete or partial tinnitus relief) can last from seconds to several minutes. Most people with tinnitus have some degree of RI (Meikle et al., 2004), but some (10% to 15%) note complete abolition of the tinnitus signal (Savastano, 2008). In a large data set, between 2% and 3% of individuals who experienced RI had durations of greater than 10 min (Meikle et al., 2004). Residual inhibition does not have strong implications for routine clinical application at this time, but it is a phenomenon of great interest and should be studied more. Therefore, the authors believe that measures of RI should be included in the evaluation of tinnitus.

Relaxation methods are a form of biofeedback that have been employed with patients who have chronic tinnitus. Some of the first psychological approaches to the treatment or management of tinnitus used similar techniques. The most common form of training is progressive muscular relaxation as described by Bernstein and Borkovec (1973). Through a series of exercises, the patient learns to tense and relax muscle groups. Although this approach alone may not demonstrate significant benefit, it may prove beneficial when used in conjunction with other therapeutic techniques. It also may be effective in treating or managing some of the other disorders/symptoms that are often experienced by the tinnitus sufferer. For example, many patients with tinnitus suffer from severe sleep disturbance, and this particular approach has proven to be helpful in assisting patients with general sleep disorders (Morin, Culbert, & Schwartz, 1994).

Due to the strong psychological component associated with tinnitus, cognitive behavioral therapy (CBT) for use with tinnitus patients was first recommended by Sweetow in the 1980s (see Sweetow, 2000). More recently, the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) published their clinical practice guidelines on tinnitus in which they recommend CBT as a treatment approach for persistent, bothersome tinnitus (see Tunkel et al., 2014). The CBT approach aims to provide patients with the skills needed to change negative associations and behaviors by restructuring their thoughts to be more accurate and positive (Tunkel et al., 2014). The following systematic 10-step approach is the recommended procedure for implementing CBT with tinnitus patients (Sweetow, 2000).

1. Define the problem in terms of a framework that allows for amenable solutions.

2. Identify the behaviors and thoughts affected by the tinnitus.

3. List the maladaptive strategies and cognitive distortions currently employed.

4. Distinguish between the tinnitus experience and the maladaptive behavior.

5. Identify alternative thoughts, behaviors, and strategies.

6. Encourage the patient to formulate and prioritize attainable target goals.

7. Collaboratively devise and rehearse strategies that can be measured.

8. Regularly assess success or failure of coping strategies.

9. Question and challenge unsubstantiated statements.

10. Lay a framework for maintenance of positive change.

Pharmacologic Treatment

While not the recommended first line of treatment in the management of tinnitus, numerous drugs have been investigated for the treatment of tinnitus (Elgoyhen & Langguth, 2010). These drugs include antiarrhythmics, anticonvulsants, anxiolytics, glutamate receptor antagonists, antidepressants, and other miscellaneous pharmaceuticals or homeopathic agents, including both controlled and over-the-counter medications. However, it should be noted that there are no standardized protocols for the use of these medications to treat tinnitus at this time.

Perhaps the most routinely prescribed drugs are antidepressants (Darlington & Smith, 2007). This is likely a result of the high comorbidity between tinnitus and psychological involvement. Additionally, anxiolytics have been prescribed with success in managing tinnitus in some patients. Both antidepressants and anxiolytics have been shown to result in statistically significant improvements in tinnitus patients when evaluated using a double-blind, placebo-controlled investigational approach (Johnson, Brummett, & Schleuning, 1993; Sullivan, Katon, Russo, Dobie, & Sakai, 1992). Intravenous lidocaine also has proven to be somewhat effective; however, the effect is short-lived, and there can be notable side effects (Dodson & Sismanis, 2004). Hence, the use of intravenous lidocaine is not a practical approach to the treatment of tinnitus.

Although a number of pharmacologic treatments are available, no one drug has proven to be effective in treating all tinnitus patients. In most cases, the drugs prescribed do not treat the tinnitus itself, but rather are used to manage many of symptoms that accompany tinnitus (i.e., depression, stress, and anxiety). It should also be noted that there currently are no medications that the Food and Drug Administration (FDA) has approved specifically for the treatment of tinnitus. The use of pharmacologic treatments, if employed, should be closely monitored by a physician and will likely prove most beneficial if used in conjunction with other nonpharmaceutical management strategies.

Sound Generators and Maskers

One of the earliest forms of treatment for tinnitus was the use of sound generators and maskers. This form of management can be dated to the early 1820s when the famous French physician Jean Itard described trying to “cover up the internal noise” by using various environmental noises. The first attempt to use ear-level devices to mask the tinnitus was initiated in the early to mid-1970s (see Vernon, 1975). These devices have been termed tinnitus maskers and tinnitus instruments and are officially classified by the Food and Drug Administration as therapeutic devices. Tinnitus maskers can be worn as both behind-the-ear and in-the-ear devices.

Traditional hearing aids also have been used in the management of tinnitus patients. In general, the literature indicates that the majority of patients with tinnitus receive relief of this symptom from hearing aids as well as sound generators (Berberian et al., 2017; Park et al., 2018). In fact, the AAO-HNS recommends a hearing aid evaluation as one of the primary approaches for patients with persistent, bothersome tinnitus who have comorbid hearing loss (Tunkel et al., 2014). Amplification devices such as hearing aids have proven successful because when these devices are worn by the tinnitus sufferer, ambient noise in the environment is amplified, and the patient’s tinnitus is masked. Kochkin and Tyler (2008) have reported that approximately 60% of individuals with tinnitus who were fitted with hearing aids have reported improvement in their tinnitus symptoms.

There have been many significant developments in signal processing since the time that tinnitus maskers were first introduced. At the present time, devices that combine both a traditional hearing aid and a tinnitus masker in one unit are commercially available. These instruments are appropriate for patients who may need additional tinnitus masking beyond that provided by a hearing aid alone (see Folmer, Martin, Shi, & Edlefsen, 2006, and Searchfield, 2006, for additional discussion).

Although ear-level maskers continue to be used, they are limited as a management approach in that, when they are not being worn, the tinnitus typically continues to be problematic for the patient. It is important for the clinician fitting such devices to be keenly aware of the importance of appropriate fitting techniques. This includes assessments of the patient’s tinnitus—including pitch and loudness matching, minimum masking level, and residual inhibition as outlined previously. Additionally, one must understand that there is a distinct difference between an effective versus an acceptable level of masking (Vernon & Meikle, 2000). Effective masking or “complete masking” refers to the ability to successfully cover the tinnitus so that the patient can no longer hear it, whereas an acceptable level of masking or “partial masking” refers to a situation in which the patient is provided a masking sound which offers some relief from the tinnitus. In the latter situation, the tinnitus is still present but is perceived by the patient to be of lower intensity and less of an annoyance. There are a number of factors that determine whether complete masking can be achieved for a given patient. These include such variables as the level of the tinnitus, the frequency of the tinnitus (e.g., if the tinnitus is matched to a speech frequency, it may be difficult to provide sufficient masking without affecting speech understanding), and the presence of multiple tinnitus sounds (for additional information, see Vernon & Meikle, 2000).

Neurophysiologic Rehabilitation

Tinnitus Retraining Therapy (TRT) is a multicomponent program that utilizes sound therapy along with counseling to achieve habituation of tinnitus. Tinnitus patients are categorized along a 4-point scale, with 0 suggesting a low impact on life and 4 suggesting a high impact on life with significant hyperacusis and prolonged sound-induced exacerbation (Jastreboff, 2000). The intent of TRT is to remove the negative association attached to tinnitus perception and to help the patient to habituate to the tinnitus so that it becomes less aversive (Jastreboff, 2007). This is achieved by presenting low-level, broadband acoustic stimulation, which is used to initiate and encourage tinnitus habituation. The effectiveness of TRT has been reported to be significant, with improvement in symptoms reported for up to 80% of patients (Jastreboff, Gray, & Gold, 1996). A large clinical trial of more than 800 veterans demonstrated benefit from TRT, particularly for those individuals with significant tinnitus (Henry et al., 2006).

A variety of therapeutic tools are available to assist clinicians with today’s tinnitus patients. The previous expression, “you’ll just have to live with it” rarely applies to today’s patients. What is important to understand is that, although treatment approaches are available that may help alleviate the “symptom,” there are still no cures for the disorder.