[Users' experiences with modern hearing aids. An audit]. / Brugernes erfaringer med moderne høreapparater. En audit.

INTRODUCTION: The aim of the study was to evaluate satisfaction with use and manipulation of hearing aids (HA), and to compare these parameters for analogue (A-HA), programmable (P-HA), and digital signal processing aids (DSP-HA). METHOD: An audit was made of data on users' experiences, as indicated in a questionnaire posted 3-4 months after the HA fitting. MATERIAL: Questionnaires were posted to 18,702 persons, who, during the period 1997-1999, had been provided with a HA at a median age of 77 years (range 18-98), 41.8% of whom were men, and 58.2% women. Responses were returned by 12,866 (68.8%), and, as there were no differences between the respondents and non-respondents with respect to age, gender, and distribution of HA type, the responses were considered representative. RESULTS: According to the replies, 71.5% were very satisfied/satisfied with their HA; 89% used the instrument daily/weekly, and 75% were able to manipulate the HA without problems. However, 10.7-12.7% said they never used the fitted HA. A significantly higher proportion were satisfied with A-HAs as compared to P-HAs and DSP-HAs, whereas there was no significant difference in use as a function of type. A significantly higher number of the users fitted with a DSP-HA could manipulate them, but 36.5% of these needed follow-up in contrast to 25.5% fitted with a P-HA, and 21.6% fitted with an A-HA. A significantly smaller proportion of the elderly were able to manipulate the HA. CONCLUSION: The users of modern HAs are satisfied with them, use them, and most are able to manipulate the HA without problems. The new technology has raised unrealistic expectations in the users, and the DSP-HAs account for larger costs to the national health services, because they are more expensive and the need for staff resources is greater.

Clinical study of hearing instruments: a cross-sectional longitudinal audit based on consumer experiences.

The objective of the present audit was to document improvements/changes in hearing instrument (HI) benefit in terms of use and satisfaction throughout the 1990s and compare the benefit in consumers fitted with analogue (A), programmable (P), and digital signal processing (DSP) HIs. The audit data are based on a questionnaire mailed to subjects fitted with HIs 3 to 4 months after the fitting, including questions concerning satisfaction with the HI, use of the HI, ability to manage the HI, and satisfaction with the overall services in the department. Information was obtained from 32,694 subjects (i.e., 71.2 per cent of those fitted with HIs throughout the last decade), with a median age at fitting of 78 years (range, 18-102), with a preponderance of females. No significant differences in age, gender distribution, and hearing instrument distribution were found between the respondents and non-respondents. The audit shows that there are no significant differences in any of the benefit parameters throughout the decade, irrespective of the introduction of P-HIs in 1995 and of the DSP-HIs in 1998. Thus, from the consumers' perspective, no changes have appeared in the last decade. A comparative analysis of the A-HIs, P-HIs, and DSP-HIs shows that among those provided with P-HIs and DSP-HIs, only 69.6 per cent (CI 68.1-71.0) and 65.5 per cent (CI 60.2-78.8), respectively, were very satisfied/satisfied with the HI, which is significantly less than the 73.5 per cent (CI 72.4-74.5) in those fitted with A-HIs. The daily/weekly use of all three types of HIs was similar. However, the group fitted with DSP-HIs was significantly less satisfied with the general services compared with those fitted with A-HIs and P-HIs, respectively. Based on these audit data, it is concluded that, according to the consumers, the outcome from HIs has not changed over the last decade, and a comparison between the traditional A-HIs with both P-HIs and DSP-HIs is in favour of the traditional A-HIs.

Clinical study of a digital vs an analogue hearing aid.

Digital signal processing in hearing instruments has brought new perspectives to the compensation of hearing impairment and may result in alleviation of the adverse effects of hearing problems. This study compares a commercially available digital signal processing hearing aid (HA) (Senso) with a modern analogue HA with programmable fitting (Logo). The HAs tested are identical in appearance and, in spite of a different mode of operation, the study design ensured blinding of the test subjects. Outcome parameters were: improvements in speech recognition score in noise (deltaSRSN) with the HAs; overall preference for HA; overall satisfaction; and various measures of HA performance evaluated by a self-assessment questionnaire. A total of 28 experienced HA users with sensorineural hearing impairment were included and 25 completed the trial. No significant differences were found in deltaSRSN between the two HAs. Eleven subjects indicated an overall preference for the digital HA, 10 preferred the analogue HA and 4 had no preference. Concerning overall satisfaction, 8 subjects rated the digital HA superior to the analogue one, whereas 7 indicated a superior rating for the analogue HA and 10 rated the HAs equal. Acceptability of noise from traffic was the only outcome parameter which gave a significant difference between the HAs in favour of the digital HA. It is concluded that there are no significant differences in outcome between the digital and analogue signal processing HAs tested by these experienced HA-users.

Self-reported need of information, counselling and education: needs and interests of re-applicants.

An interview study was performed to establish and evaluate the need for education and counselling of hearing aid users (HA users) in order to review present procedures of information and potential referral to the educational sector. The study comprises 102 consecutively selected hearing-impaired adults (>18 years), the only inclusion criterion being experienced HA user. The interview took place immediately after the patient's latest HA fitting appointment and consisted of 24 structured and closed questions. The findings indicate that a significant proportion of HA users, especially the elderly, do not experience a need for or show an interest in further education and counselling concerning their hearing handicap. It is concluded that the present organization of services meets the demands of a majority of re-applicants.

A double-blind cross-over study of a non-linear hearing aid.

New hearing aids are usually introduced after clinical trials. These are mostly based on subjects reports, in which it is possible that the subject's judgment of the acoustic performance might be influenced by the awareness that it is a new hearing aid which is being investigated. To examine the benefit of a new non-linear amplification circuit, a double-blind cross-over study was conducted. Two 'new' hearing aids were developed; they were identical in external appearance and differed only in that one involved ordinary linear amplification while the other employed compressive amplification (the K-amp circuit). Forty-five experienced users with sensorineural hearing loss, aged 60-80 years, used each of the aids for ten weeks, in balanced order. The subjects' need for hearing aid ranged from listening to radio and television to extensive use in all kinds of demanding listening situations. The results, using a structured questionnaire concerning real-life settings, speech reception tests and subject preferences for a particular hearing aid, showed little difference between the two hearing aids. Twenty-three subjects selected the non-linear amplification circuit, 20 subjects preferred the linear hearing aid and two chose to return to their previous aid. No consistent differences between those preferring the linear circuit and those preferring compression were found. It can be concluded that this compression amplification circuit is not significantly preferred to the traditional linear hearing aid.

Hearing instruments and health technology--an evaluation.

This contribution compares a currently worn hearing instrument (i.e. R-HI) with a programmable multiband full-dynamic range compression behind-the-ear HI (i.e. T-HI), based on subject preference for HI, and, in addition, compares the preference for a linear/ non-linear amplification-mode (i.e. L-mode/C-mode). Finally, it evaluates some health technology aspects related to the devices. N = 34 experienced HI-users at a median age of 72 years (range 22-84) completed the trial, n = 5 being monaurally, and n = 29 being binaurally fitted. The trial comprises an unblinded comparative study of the R-HI and T-HI, in either C-mode or L-mode amplification, and a double-blind crossover study evaluating the C-mode versus the L-mode amplification. The results of the unblinded study showed that 94% (n = 32/34) preferred the T-HI, whereas two subjects preferred their current HI. The double-blind crossover study concerning the preference for the C-mode and L-mode, respectively, in the T-HI, showed that 72% (n = 23/32) had a significant preference for the non-linear amplification, whereas 28% (n = 9/32) preferred the linear amplification. Provided that the price of the T-HI is kept unchanged, a health technology evaluation may imply an estimate of 30 mill. DKR added costs on a national basis, which should be taken into account within the national hearing services.

An audit of hearing rehabilitation within the health service--past and present.

The present contribution can be considered as an audit of the hearing aid rehabilitation programme as performed in Copenhagen, based on an ongoing quality assurance. A comparative analysis was performed in outcome measures between two 3-month periods in which the only change had been a transfer of the preliminary instruction in manipulation and management of hearing aid (HA) from the educational to the health sector. The data analysis was based on a questionnaire including three samples (sample A, n = 800 evaluated before the change; sample B,n = 779 after the change; and sample C, n = 73 with no change, acting as a reference). The comparison demonstrated no significant differences in the ability to manage or manipulate HA between samples A and B, and no changes were found in the reference sample, C. A significant decrease in the frequency of hearing-impaired subjects needing additional appointments in the health sector was found in sample B. Those subjects who at the HA fitting had made no request for additional educational services demonstrated a significantly higher frequency of 97% capability to manage HA at the follow-up in comparison to only 84% among those who had requested services compatible with the distribution of experienced/unexperienced HA users. The additional data analyses render no support for any effect of the educational services on the ability to manipulate and manage HA.

An audit of hearing aid quality in Denmark. II: Type of defects.

In this investigation the type of defects in hearing aids (HAs) is described, and the stability of HAs is evaluated, based on prospective longitudinal data over an observation period of 2 years. An exchange of information between the Danish national hearing health service and hearing aid manufacturers, representing the private sector, demonstrates that overall external components to which the HA-user has access, are frequently defective. However, with time, internal components, to which the HA-user has no access, are frequently defective within the first year of use, whereas external components malfunction significantly more frequently after 3 years of use. Among the dispensed hearing aids, 11% were defective at the fitting, indicating insufficient quality control by the manufacturers. A prospective longitudinal investigation of 1141 defective HAs revealed that 12% of behind-the-ear HAs become defective within the first year of use, exhibiting the greatest stability. After 2 years of use, all in-the-canal HAs are defective, while only 33% of the in-the-ear HAs remain intact. It is concluded that the established exchange of information between the public and private sectors offers valid information on the quality of HAs; that the quality and stability of HAs is insufficient; and that the quality should be improved, (based on international criteria).

An audit of hearing aid quality in Denmark.

This investigation was aimed towards an evaluation of the quality of hearing aids, dispensed from a National Hearing Health Service. During a twelve month period all subjects attending the hearing aid servicing section were recorded, and the reason for the visit noted. A total of 4450 people attended (45% males, 55% females) with a median age of 71 years, range 8-99 years. Among these 60.4% of attendances could be ascribed to defective hearing aids. Among the defective hearing aids 20.6% had been used less than one year and 91.4% of the defective aids had been used less than four years, that is within the guarantee period. The recording demonstrated that specific series of aids have a defect rate of 6.6-70.9% within the first year of use. A comparison between the frequency of defects in different types of hearing aids (BTE, ITE, ITC and other hearing aids) was performed indicating that there is a risk of 8.6% that BTE will be defective within one year of provision. As 20.6% of the applicants' defective hearing aids had been used less than one year, it is concluded that the quality of hearing aids should be improved; the hearing aid manufacturers' main categories for fault finding can be used in the audiological departments within the National Hearing Health Service; the recording offers valuable data on the quality of hearing aids, and specifically poor series can be revealed within a limited period.