Hearing Aid Selection Research Articles

Reduction in caregiver-identified problem behaviors in patients with Alzheimer disease post-hearing-aid fitting.

Studies and clinical procedures related to patients with Alzheimer disease (AD) largely have ignored the hearing ability of either the patient or caregiver. Yet the majority of treatment and investigation depends on or presupposes communication ability. Further, caregiver complaints often center around communication-based issues. Hearing deficits may be the most frequently unrecognized condition in patients with AD because patients either communicate adequately in quiet or the impairment is masked by other behavioral symptoms of AD. The current investigation identified individuals with AD with perceived and measured hearing impairment, provided amplification management, and evaluated the impact of treatment on caregiver-identified problem behaviors believed to be related to hearing status. Specifically, treatment compliance (hearing-aid use) and treatment efficacy (reduction in perceived hearing handicap and problem behaviors) were measured in the current investigation. A multiple-baseline design across individuals with multiple dependent variables was used to evaluate the reduction of problem behaviors post-hearing-aid treatment. Eight participants were included and 1 to 4 problem behaviors were significantly reduced for each patient after hearing-aid treatment. All participants were able to complete the necessary evaluation for hearing-aid fitting and wore their hearing aids between 5 and 15 hours per day by the end of the study. This investigation employed novel methodology in the areas of on-site hearing evaluation and hearing-aid selection, advanced hearing-aid technology, and primary data recording of caregiver-identified problem behaviors by caregivers.

Accuracy of predicted ear canal speech levels using the VIOLA input/output-based fitting strategy.

The Visual Input/Output Locator Algorithm (VIOLA) is a software-assisted method for prescribing amplification targets and selecting a hearing aid to match the targets. Although the procedure calls for selection and fitting of hearing aids in terms of their pure-tone input/output functions in a coupler, it is assumed that a hearing aid that matches the coupler prescription targets will produce specific amplified speech levels in the patient's ear canal. This investigation evaluated the validity of that assumption. Six hearing aids were evaluated. They were representative of linear and compression processing as well as single- and 2-channel designs. The "subject" was a KEMAR manikin with realistic assumed hearing loss and loudness perception characteristics. Each hearing aid was configured to match the subject's VIOLA prescription as closely as possible. Predicted ear canal speech levels were determined using the prescription rules and modified by the differences between coupler prescription targets and coupler performance of the actual hearing aids. With the subject wearing each hearing aid coupled to an unvented earmold, continuous speech was presented in the sound field and measured, after amplification, in the ear canal. The match between observed and predicted levels of amplified speech indicated the validity of the VIOLA assumptions under examination. The match between predicted and observed levels was good for soft speech input levels. As speech input levels increased, the differences between observed and predicted levels also increased, with the largest differences seen for loud speech inputs. When differences were seen between observed and predicted levels, they were always in the direction of lower than predicted ear canal levels. The differences between observed and predicted levels were attributed to the effects of limiting, effects of compression ratio in wide range compression, the individual subject's field-to-microphone transfer function, and the subject's individual real-ear-to-coupler level difference. Ear canal speech levels were reasonably close to predicted values, and the deviations from predicted levels were plausibly accounted for by consideration of hearing aid performance. Thus, the approach used by the VIOLA procedure holds considerable promise for extending clinical control over the complex and interactive parameters of nonlinear hearing aids. The results of this study indicate that selection and fitting of hearing aids using the current VIOLA procedure usually will result in the generation of lower than predicted ear canal speech levels, especially for loud speech inputs. However, the accuracy of the procedure could be improved substantially by modification of the software to account for the effects of limiting and those of the compression ratio in systems with compression thresholds lower than the level of unamplified loud speech.

Guidelines for Hearing Aid Fitting for Adults

The Guidelines for Hearing Aid Fitting for Adults were developed by the American Speech-Language-Hearing Association (ASHA) Ad Hoc Committee on Hearing Aid Selection and Fitting. Members of the committee are Michael Valente, chair; Ruth Bentler; Holly S. Kaplan, ex officio; Richard Seewald; Timothy Trine; Dennis Van Vliet; and Lawrence W. Higdon, Vice President for Professional Practices in Audiology, monitoring vice president.

Advances in hearing aids and cochlear implants

The science and art of selecting and fitting amplification for people with impaired hearing has never been more advanced and more complex than it is now. Scientific research and practical application has altered the standards for hearing aid fitting. Practioners must now incorporate true digital technology along with the nonstandard fitting protocols that this technology requires. Correlations between length of auditory deprivation and acclimatization to amplification are beginning to be more understood, resulting in more successful fittings. This article highlights a selection of hearing aid and cochlear implant issues published within the past year.

Quality control in pediatric hearing aid fitting

Specific hearing aid selection and careful fitting are essential for successful rehabilitation of hearing-impaired children. For this reason the different hearing aid types prescribed, the type and frequency of hearing aid insufficiencies reported and the effectiveness and regularity of our follow-ups were studied evaluating 253 followup exams in 39 children (71 ears) suffering of a sensorineural hearing loss, including all degrees, supplied with a behind-the-ear hearing aid. Most of the devices had been prescribed outside our department on an initial trial basis. After critical evaluation, the number of hearing aid types was reduced from 33 to 23 when corresponding devices failed to match well with the degrees and types of hearing losses present. A further decrease in hearing aid types could not be achieved as a consequence of many being already end-prescribed. Insufficiencies (n = 222) were found in 60% of the hearing aid evaluations: 59% involved dynamic hearing aid adjustments requiring better amplification (37%), distortion (18%) and dynamics (4%). Additionally, 16% affected hearing aid function and another 16% form (9%) and material (4%) of the otoplasty and the tube (3%). The last 9% of the deficiencies concerned the potentiometer cap: it hadn't been fitted in about half of the cases and had been lost in the other half despite being needed. Routine followup evaluations of the hearing aids occurred regularly in 76% of the cases with an effectiveness of 73%. Our results confirm the importance and necessity for pedaudiologic qualitative hearing aid controls in children.

Older Adults

Older adult successful hearing aid users demonstrated an advantage in self-perceived communication effectiveness over nonusers in selected communication situations. They were more likely than nonusers to take a proactive approach to managing difficult communication situations. Successful hearing aid users accepted their hearing loss condition. In managing their hearing loss, successful users based their decision to purchase and use hearing aids on personal information and initiative rather than being influenced by the perceptions of others. Hearing aid costs and personal appearance while wearing hearing aids were nondeterring factors in their acceptance and use. Successful hearing aid users were more tolerant of imperfections in the hearing aid delivery system and product performance than those who chose not to use amplification. Overall results suggest the need for further investigation of personality factors that influence hearing aid selection and use; increased consumer and physician education in the advantages of hearing aid use; population-specific approaches to counseling in the acceptance and use of amplification; and development of approaches to marketing hearing instruments that emphasize consumer benefit.

Estimation of nonsense syllable intelligibility

An intelligibility estimation test comprising nonsense syllables that were recorded separately, and then concatenated, is under development for hearing aid assessment. Consonant-vowel-consonant syllables (CVCs) are presented along with a visual display on a computer monitor that identifies each syllable with an animated pointer as it is presented to the listener. After presentation of a list of 50–60 CVCs, the listener is asked to estimate the consonant percent-correct score. A major advantage of the test is rapid administration. Percent-correct estimates were collected from 16 normal-hearing subjects presented with CVCs masked by a speech-shaped noise and with high- and low-pass filtered CVCs. In all test conditions, actual percent-correct scores were obtained for comparison. In noise and under filtering, estimates are slightly higher than actual scores. However, estimates increase with speech-to-noise ratio (dB) at a rate of about 4% per dB, similar to the actual percent-correct scores. The crossover frequency derived from the filtering experiment was approximately 1700 Hz, nearly identical to that reported by French and Steinberg [J. Acoust. Soc. Am. 19, 90–119 (1947)]. Hence, articulation theory principles may be applicable. This test may serve as a speedy assessment tool for evaluating and selecting hearing aids. [Work supported by NIH.]

Microcomputer Applications for Hearing Aid Selection and Fitting

An issue, and perhaps a limitation, which is common to all the software packages reviewed is: How well does the program fit into the dispenser's practice? Ideally the programs would be integrated so that, for example, the patient's name and address would not have to entered repeatedly into different software modules. An audiogram entered once would not have to be duplicated. An audiogram stored in a computer file would not also have to be stored on paper. Tympanogram information or other diagnostic tests (e.g., auditory brainstem response, word recognition scores) would be stored within the same patient record. Ideally, the software would be part of the hearing aid test systems so that real ear and coupler measures could be easily compared to the targets. The dots (representing loudness calculations) from VIOLA would appear on the screen of the test box running the hearing aid's input-output function. The same software used to select ideal characteristics of the hearing aid would also be used to adjust the aid, as in the case of a programmable. Or, for conventional hearing aids, a direct link to the manufacturer's database would be useful for matching a matrix. It would also be useful, when trying to match a target coupler gain curve, to simulate the effect of making an adjustment to a trim pot. Then, the hearing aid could be ordered online, and billing would be facilitated by the software. Perhaps the NOAH software platform, together with cooperation from hearing aid manufactures and software developers, will help make such high level integration a practical reality. While improvements will surely come, a variety of hearing aid selection programs are currently available. Each program has its own set of features, philosophy, and is geared toward different aspects of the fitting process. Some of the procedures are more abstract and theoretical, others are practical and concrete. Certain procedures emphasize the prediction of hearing aid characteristics from threshold data, while others require measurement of loudness perceptions. Hearing aid dispensers also have preferences and a perspective shaped by their personality and experiences. This dictates what they value. Some perceive the hearing aid fitting to be a conceptual experience to be researched or taught to students, others see it as a social experience shared with the patient for whom they care. Others may visualize it as an integral part of the business they have labored to create. Regardless of the perspective, each person can find something to appreciate in the software that has been reviewed. Powerful, inexpensive microcomputers are readily available. A minimal amount of time (less than a few minutes) is often needed to enter data and receive prescriptions that incorporate decades of research. Patients have more confidence in the opinions of their dispensers when they can see the reasoning that went into the recommendations. Allowing patients to watch the computer screen, even though they cannot appreciate most of the details, is an engaging process and allows them to feel they are an active participant. Hopefully, readers will be encouraged to try some of these software tools to add more science and objectivity to the art of hearing aid fitting.

The effect of test signal type and bandwidth on the categorical scaling of loudness

Recently several methods for obtaining clinical measures of loudness growth through the use of categorical scaling (CS) have been proposed for the selection of hearing aids. These methods use differing test signals or suggest frequency-specific level corrections in an attempt to reflect the loudness perception of hearing aid-processed speech. While some decisions regarding the stimuli utilized for loudness perception procedures are based on measured relationships to speech signals, the effect on loudness perception of changing signal type and bandwidth (as measured by CS) remains unclear. The relationships between the CS loudness growth of signals of differing type, (pure tones, noise bands, filtered/temporally inverted/passband speech) and bandwidth were examined for subjects with both normal and impaired hearing. Results suggest that when the bandwidth is similar (e.g., pure tone and 1/3 oct), signal type does not have significant bearing on loudness perception. As expected, increasing the bandwidth beyond the critical band affected loudness growth, as wideband speech stimuli were judged to be significantly louder than narrow-band speech at equivalent overall sound levels. In this investigation, similar loudness growth patterns were noted across category ratings for all test signal bandwidths. In contrast, loudness growth data obtained using an intelligible speech signal [Cox et al., The American Academy of Audiology (1994a)], revealed loudness growth patterns for speech were fundamentally different than those obtained for tones. Implications for hearing aid fitting strategies are discussed.

Hearing Aid Selection and Evaluation for Pre‐school Children

It is chiefly in schools for the deaf, kindergartens for the hard of hearing, and other facilities where hearing aids are fitted to children in Japan. Persons in charge of hearing aids in each school or facility, execute fitting to their own opinions, without a standard method of fitting. However, it is the general view that children should wear hearing aids regardless of hearing level and that they should learn to use their ears. In this paper, I described the fitting method in Japan. In addition, I explained in detail the fitting method that considers the functional gain which is becoming the main measurement, and introduce examples. I also explain that the effect of the hearing aid is measured by the functional gain, without the measure of insertion gain in Japan.

Hearing-aid pre-selection through a neural network.

Selection of optimal hearing aids for a patient with a particular audiogram has become increasingly difficult as the number of available models on the market has grown considerably. In order to assist the hearing-aid fitter in this work, recent programming techniques using artificial neural networks have been investigated. Artificial neural networks are capable of recognizing audiograms and relating them to suitable hearing aids. A programme to assist in the early stage of hearing-aid selection was developed using these techniques.

The perception of amplified speech by listeners with hearing loss: acoustic correlates.

Audibility-based approaches to hearing-aid selection generally have focused on the long-term average speech spectrum (LTASS). Advances in amplification technology (e.g., multiband signal processing, level-dependent frequency shaping, full dynamic range compression, adaptive compression) make it difficult to predict the audibility of short-term components of speech from the amplified LTASS. This study was designed to quantify the audibility of a specific phonemes as processed by two different hearing-aid circuits (linear and full dynamic range compression), and to investigate the relation between audibility and performance on a nonsense syllable recognition task. Data were obtained from three subjects with moderate sensorineural hearing loss. Nine unvoiced consonants were presented in two vowel contexts (/i/ and /a/) in both the pre- and post-vocalic position at three intensities. While the performance on selected conditions appeared to vary by hearing-aid type, only one subject showed a statistically significant difference between the two hearing-aid systems. Acoustic analyses revealed a variety of spectral and temporal changes to the speech signal following processing. Estimates of audibility were based upon each subject's thresholds and an acoustic analysis of the amplified signal that varied across phonemes and consonant position. A signal detection approach was used to predict performance from a simple measure of audibility.

Using Loudness Data for Hearing Aid Selection: The IHAFF Approach

Using Loudness Data for Hearing Aid Selection: The IHAFF Approach

Fluctuating and/or progressive sensorineural hearing loss in children

Sensorineural hearing loss (SNHL) which is sudden in onset, fluctuating, and/or progressive complicates medical management, hearing aid selection, and individualized educational planning for a hearing-impaired child. In spite of multidisciplinary evaluation and intervention, a gradual decrease in auditory acuity may continue unabated in a significant number of cases. Intercurrent middle ear disease and inconsistent audiologic technique can account for threshold variation in some cases. The study population consisted of 229 children (132 boys; 97 girls) aged 1 to 19.9 years at first audiogram which revealed at least a mild degree of sensorineural hearing loss in one or both ears (35 unilateral), and who demonstrated threshold variation of 10 dB or more in at least one ear at one or more of the standard audiometric test frequencies (250, 500, 1000, 2000, 4000, and 8000 Hz) and were without concurrent middle ear disease (mean length of follow-up, 4.9 years; mean number of audiograms, 10.3). Of 365 ears demonstrating threshold variation of 10 dB or more, 22 (6%) had purely progressive losses without intercurrent upward fluctuation, 208 (57%) had fluctuating thresholds with gradually progressive losses, and 135 (37%) had intermittent threshold fluctuation without permanent deterioration. The probability of contralateral threshold fluctuation if one ear fluctuated was 0.91, while the probability of contralateral progressive SNHL if one ear progressed was 0.67. Demographic data, presumptive etiology, degree of initial SNHL, audiometric configuration, and symmetry of threshold variation were considered as potential predictors of the likelihood of threshold fluctuation and/or progression.

高齢者の補聴器用電池外耳道異物２症例

We have treated two patients with foreign body reactions to a hearing aid battery in the external ear canal. Both were elderly users of the canal type of hearing aid. The button battery produced severe tissue destruction. One of the patients had total facial paralysis. A button battery foreign body in the external ear canal can produce extensive necrosis. A review of the literature shows that elderly users are at high risk. The authors stress that otolaryngologists should take part in the selection of hearing aids and provide detailed advice about their use, especially by elderly users.

Signal Delivery/Real Ear Measurement

This report describes a signal delivery/real ear measurement system for application in the hearing aid selection and fitting process. This signal delivery/real ear measurement system provides a means for quantifying a listener's auditory characteristics (e.g., thresholds, loudness discomfort levels) in a manner that is compatible with electroacoustic measures of hearing aid performance. The signal delivery/real ear measurement system consists of a button-type hearing aid receiver coupled to the listener's personal earmold, and a probe tube microphone system to measure the signal level within the occluded ear canal. This signal delivery/real ear measurement system was used to measure detection thresholds and loudness discomfort levels in severe/profoundly hearing-impaired school-age children, with results indicating good test-retest reliability in behavioral responses. The findings presented in this report relate to the intersession electroacoustic variability associated with this instrumentation. In addition, the potential application of this or a similar system for measuring real ear to 2-cc coupler difference values is illustrated and discussed.

Paired comparison judgments for hearing aid selection in children : Eisenberg L.S.; Levitt H.Ear Hear. (1991) 12/6 (417–430)

Paired comparison judgments for hearing aid selection in children : Eisenberg L.S.; Levitt H.Ear Hear. (1991) 12/6 (417–430)

Paired Comparison Judgments for Hearing Aid Selection in Children

Three experiments were conducted to investigate the feasibility of using a paired comparison technique to select hearing aids for children. The first two experiments determined the age at which normal-hearing children and hearing-impaired children with mild to moderately severe sensorineural hearing loss could be expected to meet criteria on a paired comparison task involving judgments of auditory clarity. Of 25 normal-hearing children between the ages of 4.0 and 6.4 yr, five out of five children between 6.0 and 6.4 yr of age passed the auditory paired comparison task. Of 10 hearing-impaired children between the ages of 5.5 and 7.4 yr, five out of five children between 6.5 and 7.4 yr of age passed the auditory paired comparison task. In Experiment 3, eight hearing-impaired children between the ages of 5.7 and 7.8 yr judged the clarity of seven hearing aids in two paired comparison, round robin tournaments. The results showed that correlations between the two tournaments were moderate to strong for six children and weak for two children. Of the six children with stronger correlations between tournaments, correlations between paired comparison judgments and phoneme identification scores were moderate to strong for four children and weak for two children. When compared with a hearing aid that approximated a standard prescription, the hearing aid selected by the paired comparison technique neither degraded nor enhanced speech intelligibility. Results from this study indicate that a paired comparison technique is feasible for use with hearing-impaired children 6.5 yr of age, and occasionally younger, who exhibit mild to moderately severe sensorineural hearing loss and are capable of performing the task reliably.

Individual Differences in Speech Recognition Ability

Hearing-impaired listeners with similar audiometric configurations often demonstrate varying abilities to understand speech in the presence of noise and/or reverberation. To date, however, it is unclear which auditory mechanisms are responsible for these perceptual deficits. This lack of information is unfortunate, as individual susceptibility to noise and reverberation may explain why hearing-impaired listeners receive varying degrees of benefit from rehabilitative strategies. The present discussion will examine: (1) individual speech recognition susceptibility to noise and reverberation in hearing-impaired listeners and (2) auditory and cognitive hypotheses to explain individual differences in speech recognition performance. Theoretical and clinical implications for hearing aid selection procedures will be discussed.

近畿大学補聴器外来の現況と7年間の臨床統計

A statistical study was made on 630 patients with hearing impairment who visited our outpatient hearing aid service department between 1984 and 1990. A statistical observation was done for sex, age, classification of hearing impairment, pure tone hearing level, configuration of pure tone audiogram, speech reception threshold, speech discrimination score and various kinds of examination for hearing aid selection such as speech reception threshold, speech discrimination score using a loudspeaker system and estimation of patients'satisfaction by magnitude estimation. We have investigated the methodology of estimation of selected hearing aids through the clinical activity in our hearing aid clinic. We took notice of two points, speech discrimination performance and patients preference for hearing aids. These two factors were studied in detail and discussed from the point of view of patients' benefit. Although the group data were analyzed in this statistical study, the results of examination should be utilized as carefully as possible with consideration of each patient's condition.