Prevalence of cochlear implants in postlingually deafened adults in a Swedish region.

Cochlear implantation (CI) rates vary between countries, depending on identification routines and economic restrictions. The present study aimed at determining the prevalence of CIs in postlingually deafened, aged 20-69 years old, in Göteborg, Sweden. Three patient databases with information on PTA, a questionnaire, medical records and consultations identified 88 subjects with sensorineural hearing loss >/=80 dB HL (PTA of 500, 1000, 3000 Hz), PB word score of

Psychological general well-being (quality of life) in patients with cochlear implants: importance of social environment and age.

The purpose of this study was to investigate the variables that affect psychological general well-being (quality of life) in patients with cochlear implants (CIs). The study sample consists of 96 adult patients with a CI, aged 24 86 years (Mean = 61.8 yrs; SD = 15.3 yrs). 48 were patients from the Sahlgrenska University Hospital in Sweden and 48 were patients from the University of Florida, USA. The Psychological General Well-being Index and the International Outcome Inventory-Cochlear implants were used in collecting data. Possible independent variables were socioeconomic factors such as age, gender, nationality, living arrangement, education, and social support; as well as length of time since implantation, age when hearing loss became a problem, and subjective benefit of the CI. A stepwise multiple regression analysis showed that 49% of the variance was explained by attitudes from others, restricted social participation, perceived social support and age.

Comparison of calculated, measured and self-assessed intelligibility of speech in noise for hearing-aid users.

The Speech Intelligibility Index (SII) was used along with paired-comparison judgements and speech recognition scores to compare the speech intelligibility provided by two hearing-aid frequency responses in two different background noises. The purpose was to validate an SII-based procedure. Test subjects were 26 hearing-aid users representing a wide range of hearing loss configurations. One hearing-aid setting was in close agreement with the NAL-R prescription, whereas the other setting was achieved by reducing the high-frequency gain by about 10 dB compared to NAL-R. There were good overall agreements between results of the three methods. Average speech recognition scores were about 4 percentage points higher for the NAL-R frequency response, which also was subjectively judged as significantly better in terms of speech intelligibility. The SII based procedure was found to be suitable for comparing hearing-aid characteristics within subjects.

Does having a job improve the quality of life among post-lingually deafened Swedish adults with severe-profound hearing impairment?

The purpose of the present study was to measure health-related quality of life (HRQL), personal harmony and work-induced problems, and to identify typical personal traits among Swedish adults with a severe-profound hearing impairment who were employed full-time. In comparison with hearing people aged <65 years, the hearing-impaired individuals working full-time differed only as regards energy and social isolation. Compared to another group of hearing-impaired subjects (working either part-time or retired) the study group scored better on most dimensions. Personal harmony of the hearing-impaired group working full-time did not differ from that of average employed Swedish people. The work situation of the group was generally reported to be busy but rewarding, especially concerning contact with fellow workers and management. Among various personal traits examined, strong will-power and stress tolerance were the most significant. However, due to the small sample size, it is not possible to state that the results indicate a general situation or were just due to the study subjects constituting an elite sample of hearing-impaired individuals.

Coping with post-lingual severe-profound hearing impairment: a grounded theory study.

The purpose of this study was to describe the experiences of coping with demanding auditory situations in everyday life from the perspective of individuals with severe-profound hearing impairment. Seventeen individuals (11 women and 6 men), with post-lingual severe-profound hearing impairment participated in the study. All were patients at the Department of Audiology, Sahlgrenska University Hospital in Göteborg, Sweden. Inclusion criteria were a hearing impairment exceeding 70 dB HL at the frequency of 1 kHz in the better ear, and full-time employment. Data were assessed by in-depth interviews lasting about one hour. The interviews were transcribed verbatim and analysed line-by-in line in accordance with the grounded theory tradition. Six theoretical constructs, or categories, were grounded in the data. These categories were labelled 'coaching', 'belonging to two worlds', 'self-efficacy', 'hardiness' and 'directing coping strategies'. In a grounded theory the central phenomenon on which all the other categories are integrated is known as the 'core category'. The core category, which emerged in the present study, was labelled 'finding flow and entering a positive circle'. This was described as a condition necessary for successful coping with the demanding situation of being a profoundly hearing-impaired person working full-time. According to the core category, there is a small 'margin' within the positive circle (a space where smaller mistakes may occur). However, if mistakes are too severe, or too many, individuals will no longer find flow in the positive circle, rather they enter a negative circle. In the present study subjects' personalities were characterized by hardiness. It is suggested that coaching behaviour and the hearing-impaired individuals' personality dispositions of hardiness and self-efficacy function as resistance resources, buffering stressful events in everyday life.

Severe-profound hearing impairment and health-related quality of life among post-lingual deafened Swedish adults.

Health-related quality of life (HRQL) was measured with the Nottingham Health Profile (NHP) in 311 Swedish adults suffering from severe-profound hearing impairment (sensorineural hearing loss in the better ear of > or = 70 dB HL at a frequency of 1.0 kHz) for comparisons with a normal-hearing population. The subjects completed NHP and a questionnaire regarding bio-psycho-social status. Generally, subjects with profound hearing loss reported lower HRQL. Significant differences were obtained for lack of energy, emotional reactions and social isolation. Females with profound impaired hearing tended overall to have lower HRQL than the males. The persons with severe-profound hearing impairment working full-time reported higher HRQL than those with a partial or full disablement pension and were comparable with the hearing population. Severe-profound hearing impairment is associated with an impact on HRQL of the sufferers, especially their emotional and social coping and energy resources. The profound hearing-impaired persons seem to constitute a risk group for worse psychosocial adjustment and need greater attention and support.

Psychometric evaluation of the Gothenburg Profile for measurement of experienced hearing disability and handicap: applications with new hearing aid candidates and experienced hearing aid users.

The Gothenburg Profile (GP) for measurement of experienced hearing disability and handicap was developed with content partly taken from the shortened Hearing Measurement Scale (HMS25). The GP consists of 20 items divided into two subscales. The first subscale measures Experienced Disability as to hearing speech (items 1-5) and sound localization (items 6-10). The second subscale targets the Experienced Handicap in social settings (items 11-15) and the personal reactions to the experienced handicap (items 16-20). In this study, data are presented for new hearing aid candidates (NewHA) (n=441) and for experienced hearing aid users (ExpHA) (n=476). Principal components factor analyses were conducted and a three-factor solution was obtained, supporting the two factors of the Experienced Disability subscale, but just confirming one factor in the Experienced Handicap subscale. The internal consistency reliability (coefficient alpha) was good (0.85 to 0.95) for the subscales as was the test-retest reliability. The ExpHA group expressed significantly greater disability (first subscale) as well as experienced handicap (second subscale). However, when controlling for hearing level the differences disappeared. The clinical use of the GP for assessment of rehabilitation needs is recommended.

Paired comparisons between the Classic 300 bone-anchored and conventional bone-conduction hearing aids in terms of sound quality and speech intelligibility.

Fourteen experienced users of bone-anchored hearing aids conducted paired comparisons of sound quality and speech intelligibility for 6 and 4 different stimuli respectively in the Classic 300 and a bone-conduction hearing aid with a steel clip. Ten paired comparisons were made for each stimulus. The patient selected the best hearing aid and rated the chosen hearing aid on a scale of 'somewhat better', 'better' and 'much better'. The Classic 300 obtained a positive assessment in terms of sound quality and speech intelligibility far more frequently. All the patients chose the Classic 300 as the best hearing aid when they assessed the sound quality of the classical music stimulus.

Perceived sound quality of three bone-anchored hearing aid models.

Eighteen patients judged the sound quality of the new Classic 300 and the existing HC 100 or HC 200 on 4 five-stage sound quality scales. Two of the scales relate to the perceptual dimensions softness and clarity, one relates to interference or noise and one relates to the overall impression. The evaluations were made, based on a questionnaire, in the patients' own homes and comprised the listening situations: TV news, music, conversation with two to three people in a noisy environment and one optional choice. The patients also stated which hearing aid was best in each situation and made a confidence rating for their selection. The patients were accustomed to wearing the HC 100 or HC 200. In these comparisons of the different bone-anchored hearing aid models, the Classic 300 received the best ratings overall. Seventeen patients changed their previously fitted hearing aid to a Classic 300 and satisfactory sound quality was undoubtedly one of the principal reasons. When it came to the confidence rating for their selections, some two-thirds of the patients stated that it was without hesitation or with little hesitation. Our overall conclusion is that the sound quality of bone-anchored hearing aids is satisfactory when it comes to clarity and overall impression. However, it may be expected that these patients with conductive losses get a better sound quality than other patients with sensorineural losses if the same type of aid is used.

Force threshold for hearing by direct bone conduction.

The bone-anchored hearing aid is connected, by means of a skin-penetrating bayonet coupling, to an implanted titanium fixture. Hence, direct bone conduction (dbc) excitation is used. Since no international standard of audiometric zero for dbc force threshold exists, it is of general interest to determine the dbc force threshold for normal hearing subjects. Two different methods have previously been applied to estimate the relation between bone conduction (bc) and dbc thresholds. One preliminary problem was to make a measurement of the output-force level of dbc transducers, which is equivalent to the situation in situ. A skull simulator, TU-1000, has been designed for measuring the output-force level of dbc transducers. The skull simulator does, in an adequate way, reflect the mechanical point impedance of the human skull. This opportunity to determine equivalent dbc force thresholds has motivated the present study in which a linear relation between the dbc force threshold and the bc force threshold was estimated. The estimate found in the present study conforms fairly well with the two previously found estimates. It is suggested that the estimate found in the present study be used as the reference equivalent threshold force level for dbc.

Listening strategies and benefits when using a programmable hearing instrument with eight programs.

The main argument for purchasing a programmable hearing instrument with multiple programs is the assumption that different program settings can be used in acoustically different listening environments. The presumed advantages of the 3M Model 8200 programmable hearing instrument have been investigated in three clinical trials. This paper is a summary of the results. The evaluations were based on protocols and diary booklets where the patients indicated the selected listening situation versus program number. The Datalogging feature of the instrument, measuring the total on-time and the on-time per program, provided a unique support of the evaluation. The results indicated that most patients use 2-5 different programs, and have 2-4 programs fitted for their specific listening environments ("spotlight-listening"). It will, however, be difficult to develop general prescriptive formulas, as the listening pattern and environments differ across subjects.

Allergic contact dermatitis from the earmolds of hearing aids.

Hearing aid users with longstanding and severe dermatitis in the ear canal were examined by a dermatologist and patch tested. In 6 of 22 (27%) patients, contact allergy to the earmold material was found. Four of the six had a positive test reaction to methyl methacrylate and two also to triethyleneglycol dimethacrylate and urethane dimethacrylate. Positive patch test reactions to substances used for topical treatment were found as well. Routines including liberal patch testing for this group of patients are suggested.

Sound quality and speech reception for prescribed hearing aid frequency responses.

Four different prescriptions of hearing aid insertion gain versus frequency were validated with a group of 26 moderately hearing-impaired, elderly hearing aid users. Three prescriptions were based on calculating the loudness and articulation index (AI) for aided speech, and ranged from a frequency response with moderate high-frequency emphasis, restoring normal loudness for speech peaks, to a response with the greatest high-frequency emphasis, maximizing the AI. The fourth prescription was a well-established formula of the half-gain type. The frequency responses were evaluated by paired comparison ratings of the pleasantness and intelligibility of speech in noise, and by speech identification tests in noise. The subjects rated the flattest response as significantly more pleasant than the other responses, and significantly more intelligible than the prescription with maximal high-frequency emphasis. There were no detectable differences in signal/noise ratios required for 50% speech identification. These results indicate that a prescription that restores normal loudness for speech peaks in each critical band is probably more easily accepted than either a procedure which is intended to make all speech bands equally loud, or a prescription which maximizes the AI.

Ten years of experience with the Swedish bone-anchored hearing system.

In 1977, a new phase began in hearing rehabilitation of patients with chronic middle and external diseases and atresias. Thus far, these patients have had to rely on conventional bone conduction and air conduction devices that for various reasons give poor rehabilitation. The principle of the new treatment, made possible by the Swedish bone-anchored hearing system, is simple: sound vibrations are directly transmitted to the skull bone via a skin-penetrating titanium implant and then are further transmitted to the cochlea, bypassing the middle ear. The present paper summarizes our results in 147 patients over 10 years, including a total of 6,334 follow-up months. No significant rate of skin infections was observed. In over 93% of the observations, no sign of adverse skin reaction was seen. When herein-suggested indications for treatment with the bone-anchored sound processor HC-200 are followed, the success rate is over 90%. The improved quality of life reported by the patients is a combination of improved quality of sound, improved comfort, and relief from middle ear and ear canal disease occasioned by conventional hearing aids.

Preferred hearing aid gain in everyday use after prescriptive fitting.

The insertion gain preferred by a group of 26 moderately hearing-impaired, elderly hearing-aid users was investigated in everyday listening situations. The subjects used monaural behind-the-ear aids, carefully fitted according to a prescription formula of the half-gain type, validated and used at National Acoustic Laboratories, Australia. The fitting was checked with real-ear measurements of insertion gain and reviewed at one or more follow-up sessions. The subjects were strictly instructed to try the recommended volume control setting before reporting which setting they preferred. The prescription significantly over-estimated preferred gain by about 7 dB. No correlation could be detected between prescribed versus preferred gain differences and the amount of previous hearing-aid use or the degree of subjective hearing problems.

Clinical trials with a programmable hearing aid set for various listening environments.

A conventional hearing aid has a frequency response that does not change much at normal listening levels. It is therefore unlikely that optimal speech intelligibility and optimal listening comfort can be obtained simultaneously, or in different listening environments. With a programmable hearing aid with multiple memories the listener can choose between a range of sound pictures, which increases the chance of finding a suitable frequency curve for each listening situation. The programmable hearing aid with eight separate settings stored in eight memories, was compared with personal hearing aids fitted according to the recommendations of the National Acoustic Laboratories (NAL) by 22 experienced hearing aid users. One memory of the programmable hearing aid was initially fitted according to the NAL recommendation. The other memories were programmed to give variations around that recommendation. One aim was to investigate whether the hearing-impaired user took advantage of different frequency responses to achieve listening improvements in acoustically different environments. Another aim was to evaluate the ergonomic and acoustical features of the programmable hearing aid, compared with other well fitted hearing aids. The evaluations were based on comparisons of the test hearing aid to the personal aid for each subject, looking at speech tests, direct paired comparison judgements, sound quality judgements and interviews. A majority of the subjects experienced substantial benefit from being able to use different frequency response curves in different environments. With the test hearing aid the subjects performed better in speech discrimination tests in noise.(ABSTRACT TRUNCATED AT 250 WORDS)

The active fitting (AF) programme of hearing aids: a psychological perspective.

Rehabilitation of the majority of hearing handicapped in Sweden consists of hearing aid fitting, provision of technical devices and information during about four visits to a Hearing Centre. Generally there is no structured guidance of the hearing handicapped on how to proceed with the hearing aid at home between appointments. A programme of active fitting (AF) of hearing aids, with a task-oriented diary, 'Try Your Hearing Aid' as a basic part, was therefore developed. We conducted a series of studies from 1985 to 1988 with the aim of investigating the benefit and applicability of the programme. A total of 128 new hearing aid candidates participated in three studies at the Sahlgrens hospital and at four other hearing centres in smaller Swedish towns. In a controlled study the AF group was more positive to their hearing aids and to the fitting period after 10 months. They used their hearing aids more frequently and felt psychologically more secure with them. It was established that the AF programme could well be applied in the clinical routine for a majority of new hearing aid patients. Old age per se was not found to be a relevant exclusion criterion. The positive outcome of the AF programme has stimulated the Swedish Institute of the Handicapped to print 'Try Your Hearing Aid' with a manual, and to introduce it to all hearing centres in Sweden.

Multi-programmable hearing aid.

A basic problem in hearing-aid fitting is the difficulty in finding one setting optimal to all listening situations that might occur. The objective was to develop a behind-the-ear hearing-aid with a very flexible analog signal processor which is digitally controlled, and a memory with logic, so that the hearing-impaired person can select from eight completely different fittings. To program and adjust this multi-programmable hearing-aid (called MemoryMate) a hearing evaluation and recommendation system (called Master-Fit) has been developed, based on an IBM PS/2 computer. This system offers the dispenser prescriptive fitting methods and performance of real ear measurements. It can be used to manage a client database. Preliminary results from a clinical study conducted in 1988 are presented. The paper also describes the uniqueness of this multi-programmable hearing aid as a powerful new research tool.

Tinnitus--a study of its prevalence and characteristics.

Three thousand six hundred randomly selected adults in the city of Gothenburg (425,000 inhabitants) stratified by age and gender, were questioned by mail concerning tinnitus. We received 66% useful answers, 14.2% suffered from tinnitus 'often' or 'always'. Tinnitus was more common in males than in females. Tinnitus was much more common in the left than in the right ear. 2.4% of the whole population suffered from the worst severity degree, 'tinnitus plagues me all day'. Tinnitus was clearly more common with hearing loss than with subjectively normal hearing. Sleep disturbances were common and increased with tinnitus severity. A majority of the questioned subjects wanted further examination and treatment.

Treatment of tinnitus: a controlled comparison of masking and placebo.

Seventeen out of 21 patients with severe tinnitus rated their tinnitus intensity during a baseline period, during treatment with a portable masker, and during a period with a comparable placebo apparatus. Group analyses showed no significant differences between any of the three periods. Seven patients showed significantly reduced tinnitus intensity ratings during the masker period; five of them also did so during the placebo treatment. After each of the treatment periods, the 21 patients answered a questionnaire about specific (tinnitus related) and general beneficial effects experienced during treatment. Specific, but not general, effects were more pronounced during masker than during placebo treatment. In conclusion, masker treatment is not unequivocally superior to placebo; there is some evidence, however, for the placebo treatment effects to be more 'nonspecific' than effects observed during masker treatment.