|While todays seniors are healthier than ever before, aging-related disabilities are still a significant factor when considering their needs. This article describes several age-related problems of older adults and suggests ways in which the hearing care professional can be proactive in addressing their special needs.|
The provision of hearing aid related services is commonly centered on audiometric thresholds and/or loudness growth functions and counseling of clients. However, when the clients are older adults (65 years and above), it is sometimes necessary to consider several health issues that are unrelated to hearing. This article describes various health problems of older adults and the obstacles that these problems may pose for hearing instrument related service delivery. Consideration of these issues have the potential to improve overall service delivery and customer satisfaction, which may in turn result in increased utilization of hearing instruments by all client demographic groups.
It should be evident that the problems described below are not limited only to older adults, and this paper does not intend to make sweeping generalizations about the vast, multifaceted populations of older clientsmany of whom are healthier than people decades younger than themselves. Instead, the following is intended to point out the special needs of some older adult clients, and provide recommendations on how hearing care professionals can better assist these people through the hearing care process.
Larsen et al.1 provide a summary of visual problems that exist in older individuals. Untreated visual impairment and eye disorders are known to affect a substantial proportion of older adults.2 These problems, in combination with hearing loss, can worsen the communication handicap.
Presbyopia: Many older individuals suffer from presbyopia (farsightedness), which refers to a decreased ability of the eye lens to change in order to focus clearly on close objects. An older client, for example, may experience difficulty in removing cerumen from hearing instrument receiver tubing. Use of a magnifying lens during the demonstration of proper hearing instrument care procedures is often useful. It sends the subtle message that this is something that needs to be done and that everyone may find this type of close work taxing on the eyes. The older individual should be encouraged to buy and use a magnifying lens at home.
For explanation of the audiometric results, large audiograms with clearly marked symbols for the left and the right ear are useful. Instead of asking the client if they can see the audiogram (which frequently results in a polite/automatic yes response), the hearing care professional may choose to ask the client to read one of the numbers (decibels) by pointing to it. Clients frequently reach for their reading glasses when asked, Can you read this number?
Among individuals over age 70, approximately 91.5% need glasses.3 Therefore, the font size on any handouts or other printed materials should be suitably large (i.e., 12-point type or larger). An explanation and demonstration of how better vision can improve speech perception should be offered to older clients, and clients should be encouraged to undergo annual check-ups for their vision.
Cataracts: Older individuals may suffer from blurred vision due to untreated cataracts. This may result in reduced understanding of test results and the use and care procedures for the hearing instruments. This is one more persuasive reason why a significant other should be involved in all the aspects of the hearing instrument process.
Difficulty with dimly lit environments: It is a temptation to use dark lighting in a hearing care office to create a subdued, relaxed feeling for clients. Unfortunately, most older people need stronger lighting than their younger counterparts; on average, an older adult needs 2 to 3 times as much light as a 20-year-old. Care should be taken that all instructions and demonstrations about hearing instrument use and care occur in well-lighted areas.
Decreased color discrimination: Some older adults have difficulty identifying the blue color that is commonly used on audiograms to denote the hearing thresholds of the left ear. In many cases, they will perceive dark-blue colors as black. Older adults have an easier time identifying the red color that is used to indicate the right ear responses on the audiogram. Thus, during explanation of the audiogram, it may be more useful to say that the red circles indicate the softest audible sounds for the right ear, and the Xs indicate the softest audible sounds in the left ear. For hearing instruments, the right aid can be identified by the red (Red for Right) dot, and the left aid with the bluish-black dot.
Similarly, written material (e.g., handouts) should be printed with black ink on white (or light yellow) paper for good color contrast and easy readability. Care should be taken to avoid using color print in any large, important block of text.
Decreased depth discrimination: Depth perception decreases with age. In particular, depth perception is worse in cases where one eye is treated for cataracts and the other eye has not been treated. Additionally, some clients choose to have monovision. Other clients may choose a prescription that allows them to use one eye for reading and the other for distance vision. These circumstances can affect depth perception depending on the degree of difference in the prescription of the two eyes. The decrease in depth perception can affect the cleaning of the cerumen from the receive tubing, battery replacement, etc. Thus, practice in these types of procedures can be helpful and may minimize the occurrence of wear or damage to the receiver tubing, battery door, etc.
Increased sensitivity to glare: Many older adults are sensitive to glare. If the hearing care professional is planning to use a computer to show various graphs, demonstrate hearing instrument features, speech tests or to administer assessment tools such as APHAB or COSI via computer, computer screen glare should be reduced as much as possible. Numerous anti-glare screens are available commercially. Although a well-lighted room is recommended for instruction and counseling, excessive direct glare on the clinicians face should also be avoided.
Decreased field of vision: Older adults sometimes suffer from a decreased field of vision. Thus, while explaining the audiogram or demonstrating the use and care of hearing instruments, the clinician should ensure that all visual objects are easily within sight of the client.
Other Problems Unrelated to Hearing Loss
Reduction in the sense of touch: Tactile sensitivity appears to decrease with age.4 Thus, an older client may not be able to feel a volume control on a hearing aid as readily as a younger person. Clients who have decreased tactile sensitivity may benefit from AGC hearing instruments. Although often useful, volume controls are not necessary on many hearing instruments with compression circuits, and thus can be eliminated. If the client insists on having a volume control, a raised control should be ordered or a hearing aid with a remote control may be recommended.
Dexterity: Older individuals may suffer from a variety of physical problems that affect their dexterity. For example, arthritis can severely affect a clients ability to manipulate hearing instruments and batteries. Likewise, an individual suffering from Parkinsons disease may have similar difficulties. In these cases, the appropriate hearing instruments and batteries should be evaluated carefully before settling on the size/style of the aids. For cosmetically sensitive clients who are interested in smaller aids, larger-size batteries should be ordered whenever possible.
Aging of the skin: The skin of older adults can be highly sensitive, irritable and may develop lesions easily. In some cases, the use of the silicone materials for ear impressions can result in severe irritation of the ear canal. Making ear impressions of powder (polymer) and liquid (monomer) materials can often help alleviate these problems.
Using a hearing instrument for the first time can also cause skin irritations. Hypoallergenic materials are recommended to prevent these irritations. In addition, slower progression in the acclimatization period of hearing instrument use must be explained and emphasized. Limited hearing instrument use in the initial adjustment period is very important in preventing skin irritationsproblems that often take a longer time to be resolved in older adults.
Memory-related problems: While many, if not most, older adults are as sharp at 80 as they were at 20, some may not remember all of the instructions provided about proper care, use and maintenance of the hearing instruments. It should be duly noted that this is not only a function of memory; it can be a criticism of the counseling process where hearing care professionals (and similar health care professionals) pack too much information into each session. When one adds to this the stress that the client may be feeling due to their hearing problem, the unfamiliar environment, a room full of testing equipment, etc., it can lead to difficulties in assimilating information for anyone at any age.
The use of hearing aids should be carefully monitored during the initial fitting period. Written instructions and frequent short sessions are particularly helpful in educating older adults on the proper use and care of their hearing aids. Whenever possible, significant-other individuals should also be included in these sessions, as well.
If an individual appears to have significant memory problems, various controls (e.g., volume, t-coil, etc.) on the hearing instrument might be minimized. Again, the selection of an automatic processing type hearing aid might be beneficial in some cases.
- Reduced flexibility: Old and young individuals alike can have difficulty with sudden changes, especially when the change involves listening to amplified sounds. A professional may decide, for example, to provide less gain in the initial fitting period and increase gain slowly during subsequent office visits. The advantage of this procedure is that the change in gain is gradual; the disadvantage is that the change may occur 2-3 times, which may be difficult for older individuals. Some digital instruments use 2-3 adaptation stages in the hearing instrument fitting software. An older individual who is fitted at Step 1 initially may have difficulty in adjusting to any more changes later. While it may be difficult to predict who can benefit from these approaches, a better method may be to start at Stage 2, so that the individual has sufficient gain and does not have to go through 2-3 changes.
Slower processing rates: Older adults sometimes suffer from slower processing rates.6 Continuous inputs of signals at fast rates can be difficult for some older people to process efficiently. For example, Rawool7 demonstrated less efficient processing of faster click stimuli within the auditory pathways of older individuals. Lack of consideration for this slower processing rate can lead to inaccurate pure tone and speech audiometric results, which can, in turn, result in a poorly fitted hearing instrument.
Hearing care professionals should allow sufficient time between test stimuli for older people to respond. Additionally, informational counseling about test results, hearing instruments and the use, care and maintenance of the devices should also be provided at a slightly slower pace. Studies have demonstrated that elderly patients benefit from clear-style speech that includes a decreased rate of words and increased duration of phonemes.8,9 The clinician should adopt clear speech during counseling, and encourage its use for the client and his/her significant others at home.
Central auditory problems: Schuknecht & Gacek10 noted that the loss of auditory neurons is the most consistent pathologic change in the aging ear. This loss of neurons begins at an early age and continues throughout life. Otte et al.11 counted the neurons in cochleae from 100 hearing ears of individuals who showed no evidence of diseases affecting the neurons. The neural populations decreased from 36,918 for the individuals in the first decade to 18,626 for those in the ninth decade, with a pattern that suggests a linear progressive loss of about 2,100 auditory neurons per decade of life.
Due to the possibility of central auditory problems, the amplified signals reaching the cochlea may not always be processed efficiently by the central auditory system. Stach et al.12 showed that the prevalence of central presbycusis increases with age, and it is prevalent in 95% of individuals older than age 80. Givens et al.13 demonstrated statistically significant correlation for scores on certain central auditory tests and hearing aid satisfaction. Approximately 29.6% consumers report non-use of hearing instruments due to minimal or non-existent benefit from the device.14 Many of these consumers report that their hearing aids amplify, but they have difficulty understanding speech. During pre-fitting counseling, any possibility of central auditory problems should be discussed. Older adults should be aware that, although the hearing instrument will help improve the audibility of sounds which are essential for sound processing, it will not help in actually processing the sounds for meaningful interpretation of the incoming signals. However, with consistent use of the hearing instruments, the auditory system may reorganize and learn to use the incoming signals more efficiently. An older adult who has unrealistically high expectations about the hearing instrument and is not provided with this information may become discouraged quickly once he/she starts using the aid.
Central auditory reorganization: Often older adults have a hearing impairment that has existed over many years. In such cases, the physiological and/or anatomical properties of the central auditory system can be changed due to auditory deprivation.15 Rawool16 examined the relationship between speech recognition scores and ABRs in hearing-impaired subjects who were selected based on fairly similar audiograms but different speech recognition scores. Using the Spearman rank-order correlation coefficient, a significant relationship between speech recognition scores and latencies of Wave I and II of the auditory brainstem response was found. These latencies were prolonged in listeners with poor speech recognition, suggesting the possibility of secondary degeneration in the auditory nerve due to auditory deprivation.
The alterations in the central auditory system are more profound where the hearing loss is more severe. Thus, if the adult has a severe high frequency loss, the neural areas that are usually responsive to higher frequencies may become tuned to lower frequencies.17 In such cases, only consistent use of the hearing instrument over a long period would lead to secondary cortical reorganization, allowing the neurons to respond to high frequency stimuli. This also suggests that, during the initial fitting period, the client may not be able to make optimal use of the amplified high frequency sounds to enhance speech comprehension.
Increase in central auditory gain: Some studies show that the gain of the central auditory pathway increases following inner hair cell loss to compensate for the reduced input from the cochlea.18 Thus, if a client has a 50 dB HL hearing threshold in the higher frequencies, provision of half or 1/3 gain may result in over-amplification and discomfort/annoyance. For such clients, minimal gain in the high frequencies is recommended in the initial adjustment period, and special attention may be given relative to UCLs.
Increased interference from environmental noise: Older adults frequently have very low tolerance to background noise. Investigators have shown that the speech understanding abilities of older individuals are more affected by noise even when they have normal peripheral sensitivity.19 Binaural hearing instruments should always be recommended (for bilateral losses) to improve signal-to-noise ratio. Clients should be taught assertive techniques to control or minimize the background noise in their communication environments. Additionally, increasing evidence points to the benefits of directional hearing instruments.
Older individuals also may be more sensitive to the hearing instrument circuit noise if they have normal hearing in the lower frequencies. Some hearing instruments have an audible circuit noise hiss in the lower frequencies.20 This circuit noise is usually not included in the specification data. Therefore, the clinician should measure the circuit noise in the lower frequencies. and hearing instruments with lower circuit noise should be ordered for those individuals who have normal sensitivity in the lower frequencies. u
1. Larsen PD, Hazen SE, Hoot Martin JL: Assessment and management of sensory loss in elderly patients. AORN Jour 1997; 65 (2): 432-436.
2. Reidy A; Minassian DC; Vafidis G, Joseph J, Farrow S, Wu J, Desai P & Connolly A: Prevalence of serious eye disease and visual impairment in a north London population: Population based, cross sectional study. Brit Med Jour 1998; 316 (7145): 1643-1646.
3. Campbell VA, Crews JE, Moriarty DG, Zack MM & Blackman DK: Surveillance for sensory impairment, activity limitation, and health related quality of life among older adults, United States, 1993-1997. MMWR Surveillance Summaries 1999; 48(SS08): 131-156. <http://www.cdc.gov/epo/mmwr/preview/mmwrhtml/ss4808a6.htm>
4. Desrosiers J, Hebert R, Bravo G, Dutil E: Hand sensibility of healthy older people. J Amer Geriatr Soc 1996; 44 (8): 974-978.
5. Maylor EA, Vousden JI & Brown GD: Adult age differences in short-term memory for serial order: data and a model. Psychol Aging 1999; 14 (4): 572-594.
6. Birren JE & Fisher LM. Aging and speed of behavior: Possible consequences for psychological functioning. Ann Rev Psychol 1995;46:329-353.
7. Rawool VW: Effect of aging on the click-rate induced facilitation of acoustic reflex thresholds. J Gerontol Biol Sciences 1996; 51A: B124-131.
8. Schum DJ. Intelligibility of clear and conversational speech of young and elderly talkers. J Am Acad Audiol 1996; 7:212-218.
9. Helfer KS: Auditory and auditory-visual recognition of clear and conversational speech. J Amer Acad Audiol 1998; 9: 234-142.
10. Schuknecht HF & Gacek MR: Cochlear pathology in presbycusis. Ann Otol Rhino Laryngol 1993; 102: 1-16.
11. Otte J, Schuknecht HF & Kerr AG: Ganglion cell population in normal and pathological human cochleae. Implication for cochlear implantation. Laryngoscope 1978; 8: 1231-1246.
12. Stach BA, Spretnjak ML & Jerger J: The prevalence of central presbycusis in a clinical population. J Amer Acad Audiol 1990; 1(2): 109-115.
13. Givens GD, Arnold T & Hume WG: Auditory processing skills and hearing aid satisfaction in a sample of older adults. Percept Mot Skills 1998; 86: 795-801.
14. Kochkin S: Marketrak V: Why are my hearing aids are in drawer?: The consumers perspective. Hear Jour 2000; 53 (2):34-42.
15. Willott JF: Physiological plasticity in the auditory system and its possible relevance to hearing aid use, deprivation effects and acclimatization. Ear Hear 1996; 17 ( Suppl):66S-77S.
16. Rawool VW: Speech recognition scores and ABR in cochlear impairment. Scand Audiol 1989; 18:1-5.
17. Harrison RV, Nagasawa A, Smith DW, Stanton S, Mount RJ: Reorganization of auditory cortex after neonatal high frequency cochlear hearing loss. Hear Res 1991; 54 (1): 11-19.
18. Qiu C, Salvi R, Ding D & Burkard R: Inner hair cell loss leads to enhanced response amplitudes in auditory cortex of unanesthetized chinchillas: Evidence for increased system gain. Hear Res 2000; 139 (1-2): 153-171.
19. Stuart A. & Phillips DP: Word recognition in continuous and interrupted broadband noise by young normal-hearing and presbycusic listeners. Ear Hear 1996;17:478-489.
20. Rawool VW: Low frequency circuit noise in hearing aids. Proceedings of the 16th International Congress on acoustics and 135th meeting of the Acoustical Soc of America, June 1998; 3: 2203-2204.
Correspondence can be addressed to HR or Vishakha Rawool, PhD, Dept. of Audiology & Speech Pathology, Navy Hall 1, Bloomsburg Univ., Bloomsburg, PA 17815; email: [email protected]