The hearing loss for pure tones that characterizes presbycusis tends to be mild (26 to 40dBHL) or moderate (41 to 55dBHL) in the mid to high frequencies. Older adults presenting with severe-pro-found hearing loss most likely have had a long-standing hearing loss, likely aggravated by aging. The consequences of long-standing hearing loss tend to be different from those associated with a recent-onset hearing loss, requiring different forms of intervention and modifications.
Functional losses. Hearing loss is associated with depression, cognitive declines, reductions in physical functional status, and emotional and social handicaps. It is difficult to know when changes in affect and cognitive or physical functional status can be attributed to hearing loss. Hearing status should thus be considered when you assess older adults. The case of Mr. Jones demonstrates the role of hearing loss in the misdiagnosis of cognitive decline.
Many older hearing-impaired adults present with decrements in emotional function. Nearly 70% report that heating loss makes them feel nervous, 49% attribute feelings of nervousness to the heating loss, and 46% perceive themselves to be handicapped by their hearing impairment. In the social domain, 50% of hearing-impaired adults say hearing loss interferes with understanding TV and communicating with friends and relatives.
Recent investigations have explored the relationship between cognitive dysfunction and hearing loss in older adults. The risk of dementia appears to increase with increasing hearing loss, after adjustments are made for variables such as depression, age, or number of primary prescriptions.Unremediated hearing loss also worsens performance on aurally administered diagnostic tests used to quantify severity of Alzheimer’s disease.Use of hearing aids results in better scores on tests of cognitive function, suggesting improved mental status in individuals with milder forms of cognitive impairment.
Screening older patients for hearing loss
Some degree of hearing loss is experienced by 30% of individuals age 65 to 74 and 50% of those over 75. Age-related hearing loss, or presbycusis, tends to be multifactorial, caused by noise, diet, medication, disease, and/or degenerative changes from normal aging.Most older adults do not use hearing aids, and those who own them often forget to turn the unit on or routinely replace the batteries.
Although heating impairment is prevalent among older adults, it is impossible to predict its consequences. Two individuals with mild to moderate sensorineural hearing loss may react quite differently to the same hearing impairment. One may purchase hearing aids because of the need to be a part of all individual and group conversations, whereas the other may refuse a hearing aid and withdraw from social situations and deny the existence of a heating loss.
Screening. As with other chronic conditions, older adults tend to underestimate the functional effects of a given hearing impairment and postpone audio-logic rehabilitation until they experience significant psychosocial consequences. As their physician TABULAR DATA OMITTED and entry point into the hearing health-care delivery system, you therefore need to screen older adults for any handicapping hearing loss. This includes examining the patient for medical problems that could affect hearing, such as impacted cerumen, discharge from the ear, tinnitus, and head trauma.
The screening version of the Hearing Handicap Inventory for the Elderly (HHIE-S) is a 5-min-ute, 10-item questionnaire designed to assess how the patient perceives the emotional and social effects of heating loss. It is widely used by physicians to identify individuals requiring audiologic intervention.The higher the HHIE-S score, the greater the handicapping effect of a hearing impairment. Responses are highly correlated with hearing aid use, candidacy, and success.
The Welch-Allyn audioscope, a hand-held otoscope that generates tones of selected frequencies and decibel levels, is another tool for screening for heating impairment.
Audiologists are independent professionals who may work in hospitals, private practice, rehabilitationion centers, or a physician’s office. Refer patients to an audiologist if they:
* obtain a score in excess of 10 on the HHIE-S questionnaire, or
* are unable to hear the 40dBHL tone in either ear at either frequency with the Welch-Allyn screen.
Selecting good candidates for hearing aids
Unfortunately, the sensorineural hearing loss of most older hearing-impaired adults is not amenable to medical intervention. The intervention of choice is effective amplification, which includes a properly fitted hearing aid and/or an assistive listening device (ALD) in conjunction with orientation and follow-up.
The most important predictors of hearing aid candidacy in older adults are motivation and self-perception of the handicapping effects of a given hearing impairment. An HHIE score in excess of 30% is highly predictive of hearing aid candidacy. Thus, the severity of heating loss and ability to understand speech as measured by the audiometer is not the sole indicator of candidacy or benefit. Other factors that figure into the individual patient’s satisfaction with a hearing aid include:
* motivational level
* central auditory processing ability as measured by performance on speech recognition tasks in less than optimal listening conditions (eg, background noise)
* tolerance for loud noise, and
* whether a significant other is available to assist in adjustment to the hearing aid
* willingness to participate in support groups such as Self-Help for the Hard of Hearing (SHHH).