Effectiveness of Hearing Aid Manipulation Training

for Very Elderly Hearing Aid Users

By Max Stanley Chartrand, Director of Research

DigiCare^® Hearing Research & Rehabilitation    

Abstract

Maintaining independence and control over one’s life are of great concern to those over 80 years of age. An important tool in achieving this end is the amplification they wear for the correction of hearing loss. In a Likert-like pretest-posttest nonequivalent control study, we utilized a Hearing Aid Manipulation Training Protocol (HATP) to find out if elderly hearing aid users can improve their ability to use their hearing aids more optimally when exposed to a new user training paradigm. Participants included 16 elderly hearing aid users (9 female, 7 male) aged 80-92 years who have had their hearing aids for a period of three to six months, and who still have significant difficulty in proficiently handling and adjusting them. Half were trained and half were not. After two weeks of HATP training, the study group realized an average of 41% improvement in over-all hearing aid manipulation versus 9.6% improvement in controls who did not receive the VCTP training, giving the study group a net improvement in performance of 30.4%.

Introduction

    Maintaining independence and control over one’s life are of great concern to those over 80 years of age (Wilken, Walker, Sandberg, and Holcomb, 2002; Feinberg and Whitlatch, 2001; Anonymous 1989). An important tool in achieving this end can be found in the ability to realize optimal benefits in hearing aid use for individuals experiencing significant hearing impairment (Johnson and Danhauer, 2002). This can be particularly important when one considers that most diagnostic indicators that threaten an elderly individual’s independence—for example, in the initial diagnosis of Alzheimer’s Disease (AD)—are almost entirely based upon auditory tasks. Hence, for the elderly individual there is significant risk toward over-diagnosis of dementia, since most will also have uncorrected or under-corrected hearing loss (Chartrand, 2001a). So, it becomes critical for very elderly hearing impaired individuals to not only receive timely correction of hearing impairment, but also to be able to utilize such correction optimally.

    Two major challenges present in this population relative to optimal utilization of hearing aids. The first is limitations in manual dexterity. If the hearing aid user cannot properly insert, remove, and manipulate their hearing aids, they are unlikely to wear them. The second challenge deals with taking control of the listening environment. Most specifically this is determined by whether or not they can manipulate the user volume control. This is not so much a cognitive issue as an occupational one (Chartrand, 2000).

    On the first challenge (dexterity limitations), a survey compiled by this author in eleven hearing health practices during the late 1980s demonstrated that up to 93% of very elderly hearing aid patients can be trained to manipulate a user volume control. Indeed, this population was found, as a general rule, to be able to write proficiently and to utilize fine-motor skills tasks, such as knitting, sewing, crafts, artwork, and piano playing (Chartrand, 1993). In that survey, it was determined that self-confidence was the main issue relative to hearing aid use, not necessarily dexterity (Chartrand, 1993).

    On the second challenge (taking control of one’s listening environment) the hearing aid industry has generally responded by influencing the elimination of the user volume control entirely. In fact, today many manufacturers list the user volume control as an option on their order forms, giving the misleading impression to dispensing professionals that the new digital technology can automatically adjust for such natural phenomena as auditory fatigue, Eustachian tube dysfunction, abnormal loudness growth, fluctuating cochlear chemistry, and other factors that cause MCL to vary hour to hour and day to day.

    In the process, it is the feeling of this author that the industry has relegated a critical tool needed by the hearing impaired to take better control of their listening environment, as well as overcoming occlusion and other own-voice complaints (Chartrand, 2003). Meanwhile, Surr, Cord, and Walden (2001) found that 77% of hearing aid consumers prefer a user volume control, once they understand that that option is available. Experienced hearing aid users with severe losses especially demand the use of a user volume control (Ross, 2004; Chartrand, 2001b).

Purpose of this Study

    Past studies have established the link between the sense of hearing ability and cognition (Chartrand, 2001a). It is understood that, as a general rule, the very elderly hearing aid user population experiences disproportionately greater challenges using hearing aids than other hearing user populations. What has not been shown to-date is which specific training approach can best assure greater utilization of hearing aids, and as a result, promote communicative independence and control over the listening environment. In short, this is a human occupation issue, not necessarily a cognitive issue. The purpose of this study, then, is to find out if a systematic training protocol for inserting, removing, and adjusting one’s hearing aid can provide the skills necessary to sufficiently overcome those challenges.

Methods

Participants

   The population sample consisted of two groups: Group 1 (n = 8), the study group, consisting of four males and four females, averaging 84.50 of age, SD 3.90, age range 80-92; Group 2, the control group, consisting of three males and five females, averaging 86.6 years of age, SD 3.70, age range 81-90. Each participant has had two to six month’s experience with their hearing aids, and reported varying degrees of difficulty in inserting, removing, and adjusting their hearing aids. Each has also complained of still having either situational or general listening difficulties with their hearing aids following the standard post-fitting training. Participants were not filled-in as to the design or nature of the study, only that they were participating in a “hearing aid problem-solving study”.

Procedure

    Prospective participants were chosen based upon a file review of patients from the period of July 15, 2004 to February 25, 2005. Twenty-three prospective participants were given a preliminary phone interview to 1) determine if their difficulties in hearing aid utilization were still serious enough to warrant participation, and 2) if they would consent to participating in a “hearing aid problem solving study”. Subsequently, sixteen of the twenty-three patients met both criteria and were assigned a date and time for the first visit.

    The pretest was administered on a one-at-a-time basis over a seven-day period in the same designated consultation room and with the same interviewer. To assure reliability and stability, each of the nine questions were read aloud by the interviewer with the participant reading along. The participant would then be asked to respond to each question according to the response that most closely fit their current hearing aid experience.

    After the pretest was administered, those participants belonging to the control group were allowed to leave. Those in the study group were then given the first of two training sessions utilizing the Hearing Aid Manipulation Training Protocol (HATP). Session I HATP was administered over a 30-45 minute period, including instructions for specific exercises to be practiced on a daily basis until the next training session. Training Session II of HATP was conducted approximately one week later for each of the study group participants in a similar manner. One week later, the posttest was administered to both the control and study group participants. A visual illustration of this pretest-posttest nonequivalent control design is shown in figure 1 (below).

Figure 1  Visual illustration of this pretest-posttest nonequivalent control study design.

Materials

Materials used for this study consisted of:

·    A pretest-posttest questionnaire (Exhibit A). This form consisted of nine questions, three questions for of the three areas of focus: Handling the hearing aids, adjusting the volume control, and taking control of the listening environment.

·    The Hearing Aid Manipulation Training Protocol (HATP), which consisted of training given over two 30-45 minute visits. HATP was designed and tested to expand a hearing aid user’s understanding about psychoacoustics, own-voice dynamics, and utilization of hearing aids as a coping strategy to improve speech-in-noise. During each HATP session, the participant was given practice of each exercise until showing improvement in skills. They practiced each exercise on their own for a minimum of 15 minutes per day or until they felt more confident in accomplishing the task.      

·    A silicone replica of the human ear on which to practice inserting and removing a non-working hearing aid made specifically for that replica.

·    Two heavy-duty aluminum alloy tuning forks (512Hz, 1024Hz) which were sounded to help participants find a mid-line in binaural cases.

·    Reprinted articles pertaining to use of the volume control (Chartrand, 2001b) for participant home-study.

·    Earcharts, visual models and other items utilized for training.      

Measures

    To help assure consistency and validity, each question used in the pretest-posttest questionnaire was tested to determine relevance to the study question. Scaling was spaced to avoid overlap or confusion between degrees of responses. The response scale was made to reflect four scoring levels (1-4) to reflect easily identifiable degrees of difficulty, from “not at all” (1) to “once in a while” (2) to “most of the time” (3) to “all the time” (4). During the design and preliminary testing of this questionnaire, it was found that the usual Likert five-degree scale rendered responses that were too close together for this population. Therefore, the four-levels were chosen to reflect a Likert-like scale.

     Questions were grouped into groups of three, reflecting three specific areas of focus:

1.    Handling the hearing aids- Inserting and removing the hearing aids, and opening and closing the battery door.

2.    Adjusting the volume controls- Ability to recognize when volume controls have been adjusted too high (echo of own voice) or two low (occlusion of own-voice), plus recognition of auditory fatigue, which happens over the course of the day, and can affect hearing ability.

3.    Taking control of one’s listening environment- The ability to adjust hearing aid volume in extreme environments (quiet to noisy) as needed, coping with difficult listening situations (a dimly lit room), and strategizing in large area listening as needed.

    The before and after steps in the response scale of the pretest-posttest questionnaire were designed to be sensitive enough to account for variations in subjective judgments. Even so, it was expected that there would be some overlap (confusion) between test sittings given two weeks apart.

Data Analysis

     Overall pretest performance for Group 1 (n=8) was: m= 2.51, SD= 0.32, range= 1.00 compared to overall posttest performance (after HATP training) of: m=1.47, SD= 0.35, range 1.00. From these calculations, Group 1 demonstrated an overall performance improvement of 41% before we factor in Group 2 pretest-posttest differences (See figure 2).

     Overall pretest performance for Group 2 (n=8) was: m= 2.49, SD= 0.27, range= 0.60, compared to overall posttest performance at: = 1.48, SD= 0.41, range = 1.40. Hence, Group II demonstrated an overall performance of 9.6% without taking the HATP training. Taking the pretest-posttest effect of 9.6% from Group 1’s 41% will result in a real improvement level of 31.4% for Group 1. (See Figure 3).

Figure 2   Group 1 Pretest-Posttest Data & Scores

Subj ID            Sex              Age        Degree of HL         Pre             Post

Figure 3   Group 2 Pretest-Posttest Data & Scores

Subj ID            Sex              Age        Degree of HL         Pre             Post

Results/Discussion

    From this study we find significant improvement (41%) in overall performance in Group 1, all of whom received two weeks structured training utilizing the Hearing Aid Manipulation Training Protocol (HATP). This contrasts to 9.6% improvement in overall performance in Group 2, the (untrained) control group. Utilizing a nonequivalent control group provided us with greater internal validity by giving us a more exacting measure of the chance or pretest effect score. Subtracting out 9.6% (Group 2 overall improvement) from 41% (Group 1 overall improvement) gives us a net improvement for Group 1 of 30.4%, still a significant result.    

    Hearing loss is a complex condition which can be made even more complex with significant overlay from physiological, psychosocial, emotional, cognitive and motor factors. In addition, other health conditions, particularly diabetes mellitus II, artherosclerosis, and especially otosclerosis of the middle and inner ear. Therefore, it is often difficult to compare aggregate outcomes in within group studies in hearing impaired populations.

    The participants chosen for this study had to meet criteria showing they were still having post-fitting difficulties even after receiving the traditional battery of hearing aid training. For that reason, this study focused upon the learning of concepts attendant to developing additional motor skills in an effort to ease anxiety and frustration over handling and manipulating their hearing aids.

    Admittedly, accuracy factors that could not be measured in this study were subjective impressions over the actual level of difficulty. These factors can change from day to day. It is noted, for instance, that in two of the cases of control participants, they reported doing better on the pretest than on the posttest. Perhaps this is a result of other health or cognitive factors outside the auditory realm. In most cases where control group posttest item scores were better than the pretest item scores, participants honestly felt the problem was not as severe as before. These could be due to a variety of reasons, namely, rehearsal or raised awareness from taking the pretest, perceptual changes occurring over the two week time-span, and, of course, naturally occurring improvements from practice over time. These would explain the 9.6% (chance) improvement rate of the control group.   

    As stated earlier, HATP was designed to teach three main concepts. These concepts, at first glance, may appear more complex than the average elderly patient would be able to grasp. However, our experience from this study was that participants exposed to complex topics that are accompanied with visual models and which relate to specific learned motor skills achieve more confidence in manipulating their hearing aids, even when the all concepts are not grasped intellectually. For instance:

·    Model #1 (Figure 4) helps explain the rehabilitative reinforcement cycle that develops as the hearing aid user practices carrying out such tasks as inserting and removing their hearing aids. They begin by watching their hearing health professional inserting and removing a hearing aid in his/her (professional’s) own ear. Then, the user practices with a replica ear and non-working hearing aid so that they can develop spatial and eye-hand coordination skills. These skills are then transferred to inserting a hearing aid into his/her own ear. As manual dexterity improves, so does rehabilitation, which, in turn, raises cognitive awareness. From this study we noted that this cycle repeated itself with each new skill learned, and consequently, so did the user’s self-confidence.      

·    Model #2 (Figure 5) shows a visual depiction of the three main components of the “own voice” biofeedback system that is taught during HATP. It helps the hearing aid user to understand that what is perceived as “natural” is actually a perception they realize by hearing via three routes of transmission of their own voice. Hence, when they hear only the external part of their voice only, as in a tape recording, their voice sounds brighter and sometimes more metallic, without the deepening and softening effects of internal conduction and taction at the tympanic membrane.  

·    Model #3 (Figure 6) draws attention to how a user volume control is utilized to present a balance between pressure in the throat or occlusion when is turned to low, to the other extreme, when the amplified sound is too bright or with a hollow or echo sound realized when the volume control is turned too high. Also, noted is the small range between the two extremes where the voice is perceived as “natural” or “just right”. Of course, other factors, such as appropriate ear canal resonance in the amplified signal must be addressed before this depiction is meaningful (Libby, 1989). 

·    Model #4 (Figure 7) illustrates the concept that own-voice perception, as it is adjusted with a user volume control, can be detected as various levels of the human head. For instance, in the “just right” volume control position, the voice is sensed in a physical area between the lips and the nose. In the “too loud” position, the voice resonates in the sinuses above the noise and into the forehead, depending on degree of over-loudness. Probably even more important to most hearing aid users is occlusion and when own-voice speaking is detected as a pressure down into the throat. In this case, gain level is too low, leaving the internal aspect of own-voice detection the dominant one. Carried through the Arnold’s branch of the vagus and involving other cranial nerves, as well, occlusion is perceived as a pressure “downward” into the throat or even in some cases the chest (Chartrand, 2005).     

Conclusion

    Hearing loss is not a black and white condition, it is unreasonable to expect normal or even near-normal hearing correction no matter how sophisticated the technology. The goal is to improve hearing function without creating untenable artifacts, such as dexterity, own-voice, or noise management complaints. In turn, quality of life should improve.

    It is believed that this study demonstrates conclusively that real quality of life improvements can be realized in those having greater levels of difficulty when using the HATP training. Possibly, its use in hearing health practice may be particularly targeted for those with demonstrated post-fitting difficulties. With more refinement, especially in simplifying some of its complex concepts for hearing aid patients, the HATP training method may be a valuable tool in resolving hearing aid problems in the very elderly population.        

About the author

Max Stanley Chartrand serves as Director of Rehabilitation at DigiCare Hearing Research & Rehabilitation, is profoundly deaf and utilizes a cochlear implant and assistive devices. A prolific writer and lecturer in hearing healthcare, he is currently enrolled in a doctoral level Behavioral Medicine program at Northcentral University. Correspondence: www.digicare.org.

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Exhibit A

Pretest-Posttest HATP Rating Questionnaire

Instructions: From the questions below, please circle the most appropriate answer to the right that most closely describes your current hearing aid listening experience.