Biomedical subjects

A Ringdahl

Publications and source records attributed to A Ringdahl.

9 recordsLinked to original sources

PubMed1992

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.

Adult↗

PubMed1991

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.

Aged↗

PubMed1990

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.

Aged↗

PubMed1990

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.

Adolescent↗

PubMed1990

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)

Adult↗

PubMed1990

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.

Aged↗

PubMed1990

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.

Aged↗

PubMed1989

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.

Adult↗

PubMed1987

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.

Adult↗