Hearing loss associated with the aging process is commonly termed ‘presbycusis’, which comes from the Greek presbys (πρσβυς) ‘elder’ and akusis or ‘hearing’. Thus, presbycusis can be directly translated as ‘hearing in the elderly’. Both auditory and vestibular structures within the inner ear can be adversely affected by presbycusis. In fact, according to several past studies, hearing deficits associated with the aging process may begin in some individuals as early as 30 years of age and can be progressive, such that by the age of 65, approximately one-third of persons, both male and female, will suffer from significant hearing loss. These figures can rise to almost two-thirds for those people over the age of 80 (Christensen et al., 2001; NIDCD, 2002).

Within the aging process in humans, hearing loss can occur secondary to changes within the outer, middle or inner ear structures, within the brain itself, or sometimes because of changes in multiple areas of the auditory system (Martin & Jerger, 2005). When a hearing loss occurs within the outer or middle ear system, it is termed a conductive hearing loss because the conduction of the sound waves to the inner ear structures is disrupted. Conductive hearing loss is often medically or audiologically treatable and may be secondary to such problems as excessive buildup of cerumen or ear wax within the ear canal, fluid build-up within the middle ear cavity, perforations of the tympanic membrane, ossicular chain dysfunction or the effects of Paget’s disease on bone tissue. These conductive problems can usually be diagnosed within a comprehensive audiological evaluation and appropriate treatment measures can be initiated.

Hearing deficits within the inner ear system are termed sensorineural in nature. This type of hearing impairment is traced to deficiencies within the inner ear or eighth cranial nerve structures. Unlike conductive hearing loss, sensorineural hearing loss is rarely treatable by medical or surgical intervention and is therefore considered to be a permanent condition. Degenerative changes within the auditory structure of hair cells and nerve fibers within the inner ear are the primary culprit. Although genetic changes secondary to the aging process can be a potential cause of presbycusis, the most common reason for age-related changes in hearing sensitivity is associated with exposure to the intense noise levels of day-to-day living. These exposures may be industrial or recreational in nature with the interrelationship between intense noise and hearing loss well documented over the years (NIDCD, 2008). Since the 1970s, the Occupational Safety and Health Administration (OSHA, 2002) has published and enforced guidelines on hearing conservation and protection in industrial settings (Center for Disease Control and Prevention, 2013). However, industrial noise is not the only potential cause of a noise-induced hearing loss, as many noise sources within the home environment can also be loud enough to potentially affect hearing. Individual susceptibility is also a factor in determining the effects of noise on an individual. Other possible causes of sensorineural hearing loss include: vascular changes within the inner ear, including diabetic-type changes; ototoxicity; viruses that may affect the cochlea and eighth nerve tumors or lesions.

Hearing loss related to changes within the cerebral cortex of the brain is termed central hearing loss. Understanding and interpreting speech is a complex task. Unfortunately for some individuals, their outer, middle and inner ears as well as the eighth nerve may be functional, but the brain itself may fail in interpreting the signals sent by the auditory system. It is the auditory system that allows us to ‘hear’ sounds, but it is the brain that allows for the ‘interpretation’ of speech. Some people may exhibit central problems secondary to traumatic head injury, tumor or stroke and thus present difficulty in interpreting or understanding speech. The degree of injury and the area of the brain affected usually dictate the prognosis for improvement or recovery in these instances. However, a category termed ‘central auditory processing disorders’ also falls into the realm of central hearing loss. These problems are quite common across the ages but are most commonly present in older individuals. With a central auditory processing problem, the person may exhibit difficulty understanding or interpreting speech sounds when extraneous stimuli, such as background noises, are present. As one ages, structural and cortical chemical changes in the brain can occur. These changes can be exacerbated by factors such as overall health, genetics and environment. As the age-related decline of the brain occurs, auditory processing problems may become more evident. However, in some instances, therapeutic or rehabilitative measures may be available to inhibit or counteract these processing difficulties (Murphy et al., 2006).

Lastly, the condition of auditory neuropathy warrants mention. Within the evaluation of hearing loss, it can sometimes be found that, despite the presence of minimal measured hearing loss, the patient experiences very poor speech understanding in background noise situations. This condition is now able to be identified by enhanced auditory test measures, but auditory neuropathy presents significant challenges for successful rehabilitation of this auditory deficit (Hain & Micco, 2003; Roush, 2008).

Hearing loss is a common anomaly, especially among older individuals. However, hearing loss is also insidious and not always apparent to the individual, the family or primary care physician, who may be asked for an opinion. In general, people over the age of 50 should undergo a comprehensive auditory evaluation in order to determine a hearing baseline for future comparisons. However, numerous research studies generated by hearing professionals (Kochkin, 2009) continue to define the hearing-impaired as an underserved population for treatment. One of the primary reasons for this finding is a lack of desire or understanding of the symptoms of hearing impairment. In fact, it is commonly felt that hearing loss, especially in its early stages, will more commonly be noted by family or friends, rather than by individuals themselves. For example, a family member may notice the television volume is increased or the individual must frequently ask others to repeat themselves.

Although hearing-impaired individuals may experience symptoms differently, some of the more common subjective signs of hearing impairment include: (1) inability to clearly understand all or parts of conversations; this problem may be exacerbated when background noise is present; (2) frequent requests for repetitions or clarifications; (3) individual withdrawal from conversations or social situations; (4) a need to request others to raise their voices; (5) a perception that people ‘mumble’, rather than speak distinctly; (6) a perception of the voice of the hearing-impaired speaker as being too loud or too soft; (7) end-of-the-day fatigue secondary to a necessity of straining to hear (UCSF, 2013).

As previously noted, hearing loss associated with aging is termed presbycusis. Although some may continue to think of presbycusis as a factor of aging alone, it is actually the outcome of several variables that can occur within an individual’s lifespan (Rosenhall, 2001). These variables may include, but are not limited to, metabolic, vascular or renal diseases, inflammations, infections, medications, head trauma, nutritional deficits and hereditary factors. However, exposure to intense noise levels over time continues to be the most common factor in precipitating the hearing decline related to aging. In a classic study published in 1962 by Rosen et al., individuals living in a relatively noise-free environment in the Sudan showed significantly less hearing loss when compared across the ages to people living in industrialized societies. As a result of this and other studies, attempts continue to educate people about the effects of loud noise on their hearing and the importance of using hearing protective devices when exposed to such noise.

The hearing loss associated with presbycusis is usually insidious and is initially noted not as a significant and sudden decrease in hearing, but rather as a problem in understanding speech. Sound will become distorted secondary to outer and inner hair-cell damage. Many patients with presbycusis will present with the complaint of ‘I hear but cannot understand’. This initial complaint is usually a result of a decrease in hearing within the high frequency range of the inner ear cochlea. At birth the normal human ear is thought to be functional within a frequency range of 20 to 20 000 Hz. However, as the individual ages, the cochlear hair-cell function begins to diminish, especially in the higher frequencies. The cochlear change deprives the inner ear of a critical connection to the cerebral cortex. If the auditory signal is unable to reach the brain, interpretation will be lacking, resulting in a deficit or loss of auditory function. The greater the amount of hair-cell damage, the greater the amount of hearing loss and the greater the handicap imposed on the individual. Unfortunately, no medical or surgical treatments are presently available to remediate the vast majority of inner ear hearing loss. Although ongoing laboratory studies present hope in such areas as hair-cell regeneration and temporal bone transplant, it will probably be many years before such dramatic innovations are readily available. At present, the best hope for alleviation of inner ear hearing loss lies with electroacoustic devices that can assist the hearing-impaired. The most common of these is the hearing aid.

The expression of someone’s ‘ears ringing’ is not only a common phrase, but a true inner ear condition. The condition is referred to as tinnitus, and it affects as many as 50 million Americans (Kochkin et al., 2011). Tinnitus is most often described by patients as a ringing sound, but others classify it as ‘crickets’, roaring, hissing, whooshing, whistling, or even a chirping sound. The description also varies among patients in relation to the sound quality, duration and intensity of the perception. In most instances, tinnitus is a subjective sensation and, therefore, audible only to the individual suffering from the condition. However, there are rarer instances in which tinnitus is audible to others. This condition is termed ‘objective tinnitus’ and is generally related to spasms within the middle ear musculature or changes in blood flow or increased blood turbulence in the area of the ear. It should be noted that tinnitus is not a disease itself, but rather a symptom of another condition. The American Speech–Language–Hearing Association (1997–2013) has classified some of these triggering mechanisms to include hearing loss, noise trauma, head and neck injury/trauma, disease such as Menière’s disease, ototoxic medication and other health-related problems to include otosclerosis, impacted cerumen, ear infections, middle ear tumors and temporomandibular joint dysfunction.

The impact of tinnitus will vary among patients, and so the management of the condition will vary from patient to patient as well. Most tinnitus sufferers are undisturbed by the condition, but some can suffer psychologically (American Tinnitus Association, 2013). It is not uncommon for patients suffering from an intractable tinnitus to develop feelings of anxiety, lack of energy and concentration, general fatigue or even clinical depression. These problems usually develop when patients ascertain that the tinnitus condition is beyond their control and hence becomes a negative fixture within their everyday lives. Some patients will develop such fearful reactions that they may withdraw from what had previously been their everyday lifestyle.

Despite extensive research, there is not presently a cure that will silence tinnitus. Various forms of medical treatment have been attempted without significant success to this time. However, despite the lack of cure, tinnitus can be managed in many situations by treating the underlying causes or by attempting to alter the patient’s perception of the condition. Some treatment management methods include: medical treatment of the underlying issues, alternative or non-medical methods of remediation, sound therapy, hearing aids, education and counseling, or combinations of these options.

Alternative methods for treating tinnitus have included such disciplines as acupuncture, hypnosis, homeopathy, magnets, and vitamins and herb supplementation. A study conducted by Meehan, Eisenhut and Stephens in 2004 showed that of all the varied alternative methods for managing tinnitus, only hypnosis significantly improved patient relaxation and wellbeing. Also, there are no FDA-approved medications for treating tinnitus. Some tinnitus suffers may be prescribed medications to treat accompanying depression, sleeping disorders, or anxiety. It should also be mentioned that several prescription drugs label tinnitus as a potential adverse effect of the medication (Fausti, 2004; Mayo Clinic, 1998–2013).

By presenting external noise to the tinnitus patient’s ears, sound therapy is used to help decrease the perceived intensity of the tinnitus (Jastreboff & Jastreboff, 2004). White noise, music and soothing sounds like rolling waves or mountain winds are most commonly used for this type of therapy. A patient can listen to these external sounds by either wearing a device, such as a hearing aid with tinnitus treatment, or just listening to these sounds through an external speaker. Amplification from hearing aids has proven to help alleviate patients’ stress towards their tinnitus by simply adding additional sound to their environment, secondary to their hearing deficit (Kochkin et al., 2011; Newman et al., 2011). The use of hearing aids combined with the addition of external sounds has proven so effective that some hearing aid manufacturers are presently including sound therapy options in their hearing aids. Folmer and Carroll (2006) reported that ear-level-worn hearing instruments can help patients with chronic tinnitus by reducing their perception to the tinnitus and/or facilitating the habituation process.

Finally, education and counseling also need to be key components for the management of tinnitus. It is important for patients to know what mechanisms may trigger their tinnitus. Once individuals become more knowledgeable about the tinnitus condition, they may become less fearful towards the condition itself. This in turn may prepare them to move forward into an appropriate treatment paradigm (Tyler, 2006). Other counseling tools such as cognitive behavioral therapy and tinnitus retraining therapy may also attempt to guide the patient to accept, rather than react negatively towards, their tinnitus condition (Jastreboff, 2007).

No rehabilitative process can be effective without a comprehensive identification program. The current protocol for initial auditory evaluation is based upon both traditional and modern procedures. The purposes of a hearing evaluation include diagnosing conductive versus inner ear lesions, determining the need for medical or surgical referral, creating a course of rehabilitation, determining the need for site-of-lesion evaluation and determining the extent of disability. The two professions primarily involved in inner ear evaluation and treatment are otolaryngology and audiology. The otolaryngologist or ear, nose and throat specialist is a physician who is skilled in the medical treatment of auditory disease or dysfunction. Over the years, many auditory conditions that were once thought to be permanent have been found to be treatable through medical or surgical techniques. Although reversal of inner ear aging patterns has not yet been accomplished, ongoing research, including genetic modification practices, continue to show promise for the regeneration of hair-cell tissue or recovery of hair-cell damage (Ryals & Rubel, 1988; Mizutarik et al., 2013).

Audiology is the other profession involved with inner ear impairment. An audiologist is a nonphysician specialist involved with the evaluation, diagnosis and treatment of hearing and balance problems that cannot be managed medically. It is usually the realm of the audiologist to initiate and complete the comprehensive testing process necessary to identify any problem and develop a course of realistic treatment of inner ear dysfunction. The initial aspect of the auditory evaluation includes such time-tested measures as otoscopic examination and tuning-fork testing. These procedures can act as a screening mechanism to allow the professional audiologist to determine, within a reasonable degree of certainty, whether a hearing loss is present and whether it can be localized within the conductive or inner ear mechanism.

Following these initial screening procedures, the audiologist may use two other traditional hearing measures: pure-tone audiometry and speech audiometry. In pure-tone audiometry hearing thresholds are obtained at several frequencies. In pure-tone air-conduction testing, the entire auditory system is evaluated, whereas in pure-tone bone-conduction testing, only the inner ear reserve is evaluated. By comparing air conduction thresholds with bone conduction thresholds, the clinician can determine, among other things, if medical referral is indicated.

The pure-tone test results are supplemented by speech audiometry. Using speech signals to evaluate the auditory system is a tradition that has been ongoing since the earliest days of auditory testing. Speech testing cannot only be used to validate and confirm the reliability of pure tones, but also to estimate the presence or absence of any distortion that may be present within the auditory system, secondary to hair-cell damage.

Other diagnostic measures that are routinely applied include acoustic immittance testing, which is an objective measure of the peripheral auditory system and which can provide efficient information regarding that system. Pure tone, speech and acoustic immittance evaluations coupled with otoscopy and tuning-fork testing are considered the bedrock of the auditory evaluation. However, these tests can be supplemented with other measures to provide additional diagnostic and site-of-lesion information. Additional evaluations may include: