Decreased use of hearing aids following training in hearing tactics

In this report data on hearing aid use were combined from three randomized controlled studies on behavioural hearing tactics. Daily average hearing aid use at pretreatment and posttreatment were analysed for 63 older hearing-impaired persons who had either received treatment or acted as controls. Analysis showed a significant, albeit weak, decrease in daily hearing aid use for those subjects who had received the treatment. The utility of amount of hearing aid use as an indicator of rehabilitation success is discussed.     

Long-term use of hearing aids in patients with presbyacusis

By means of a prospective study, concerning the postoperative rate of ossification after cementless total hip replacement, it was due to prove the efficacy of radiotherapy in preventing periarticular ossification. In 1992 arthroplasty was followed by radiotherapy of 50 hip joints as regular therapy. The radiation was performed with a focal dose of 8 Gy. Patients with bilateral cementless total hip replacement and radiotherapy only at one side were of special interest in this study. Within the 24th postoperative week in 28 (56%) of the radiated hip joins no periarticular ossifications were found. In 20 (40%) we found ossifications grade 1, in 1 case ossification grade II and in 1 further case ossification grade III following the classification of Arcq. By 8 patients with former cementless total hip replacement without postoperative radiotherapy, a significant reduction of the ossification rate was found in the contralateral hip joint treated by postoperative radiotherapy. The rate of ossification was reduced by 28%. In correlation to reduction of periarticular ossification the increase on the overall range of motion in the radiated hip joins was 10.9%. By none of the patients treated by radiotherapy we found a disturbed healing process, a deep infection or an early loosening of the endoprosthesis. Postoperative radiotherapy as regular therapy for prophylaxis of periarticular ossification after Cementless total hip replacement can subsequently be recommended.     

Comparison of two digital hearing aids

OBJECTIVE: The objective of this investigation was to compare real and perceived benefit for two currently marketed digital hearing aids, the Oticon DigiFocus and the Widex Senso. The hearing aids have different philosophies of design and fitting strategies; as a result, it was hypothesized that there would be performance differences. DESIGN: Twenty subjects with documented sensorineural hearing losses were fit with each of the two digital hearing aids. After 4 wk of use with each hearing aid, a battery of objective and subjective tests was completed to assess hearing aid benefit. RESULTS: No significant differences were found between the hearing aids as revealed by the objective testing of speech recognition and self-report inventories of hearing aid benefit. The DigiFocus was shown by real ear measurements to provide more high-frequency gain than the Senso. The Widex Senso was preferred by 13 of the 20 subjects (seven of 10 of the new hearing aid users). This may be explained, in part, by the increased high-frequency gain provided by the Oticon DigiFocus, which was perceived as having greater "harshness." CONCLUSIONS: Based on the results of this investigation, neither hearing aid processor was shown to be superior to the other. In addition, the least amount of objective benefit was shown in the presence of background noise.     

Radio frequency clipping in hearing aids

For those patients with reduced dynamic range of hearing, accomodation of normal dynamic range of speech has always presented a problem. This paper describes a method of overcoming the problem, a method which has the added benefit of offering improved speech discrimination as well as limiting the output from a hearing aid system. The principle employed is the presentation of taped speech material processed through clipping of a radio frequency single side side band suppressed carrier signal, which is filtered to remove the Fourier components and demodulated to obtain the modified speech material. Groups of normally hearing and hearing impaired subjects undergo speech audiometry testing to assess what improvement can be effected by this system. The majority of subjects tested both normal and hearing impaired achieve improved speech discrimination when using the system described. Further once the output was set no increase in the input signal could produce a level in excess of that set by the output control.     

Presbyacusis, hearing aids and aging

This paper considers the factors of presbyacusis and age-related psychological changes in older adults in terms of their effects on the use or potential use of hearing aids as a means of improving aural communication. Data are presented on the prevalence of hearing impairment and the extent of hearing aid use in aging listeners. Four major classes of presbyacusis are described (sensory, neural, metabolic, and cochlear conduvtive) and a hearing aid prognosis is made for each type of disorder. It is shown that aging produces deficits in pure-tone thresholds, the speech reception threshold, and speech discrimination, but not all losses can be 'corrected' with a hearing aid. Binaural (stereophonic) devices are psychoacoustically superior to monaural devices; however, behavioral and personality changes in older patients often create problems of adaptation to the binaural aid. These changes may also affect the fitting of an aid and the patient's ability to learn to use it. Some practical suggestions are offered on the evaluation of hearing aids and it is emphasized that adequate orientation and counseling are typically required if hearing aid treatment is to be successful in presbyacusis.     

Procedure for clinical testing of hearing aids

Conservative treatment of thoracic outlet syndrome is frequently recommended but few studies reporting conservative management are present in literature. Thirteen out-patients with thoracic outlet syndrome (4 males, 9 females) were admitted to a conservative treatment (massage and kinesitherapy) involving the cervical spine and shoulder girdle. All the patients were satisfied with the outcome of the treatment. In particular rest symptoms completely disappeared after treatment in all patients. This study confirms the efficacy of physical therapy in the conservative treatment of patients with thoracic outlet syndrome. Further studies on long-term outcome are needed.     

On the history of mechanical hearing aids

The results of the treatment of 140 patients with diabetes mellitus complicated with purulent process are analysed. The vulnerosorption with polyphepan was used in 68 patients. Polyphepan is a natural polymer obtained from a technical lignin. The method of vulnerosorption with polyphepan is described. Positive dynamics of the local inflammatory process, shorter cleaning of the wound and the time of granulation were demonstrated. The use of the wound sorption provided the decrease of the hospital stay by 13.7 + 0.2 days.     

Intelligibility in noise using multimicrophone hearing aids

Electron probe X-ray microanalysis has been used for the last 25 years by biologists to obtain information about the distribution of elements at the cell and tissue level. During this period, progress has mainly been made through the development of more adequate techniques for specimen preparation (mainly low temperature techniques) and quantitative analysis, so that accurate analysis of the physiologically important cellular ions can be carried out. Use of in vitro systems and cell cultures may further increase the number of problems to which X-ray microanalysis can be applied. Among the numerous applications of X-ray microanalysis in cell biology and cell pathology, applications in the areas of epithelial ion transport, the role of calcium in secretory and contractile cells, and the role of ions in cell proliferation and cancer are discussed in more detail.     

An implantable microphone for electronic hearing aids

Fully implantable hearing aids and cochlea implants of the future require an implantable microphone. A hermetically sealed implantable microphone based on the idea of a microphone implanted in the posterior wall of the auditory canal, as suggested by Ohno et al. in 1988, is presented. Through consistent technological and clinical design optimization, it was possible to achieve a membrane diameter of only 4.5 mm (as opposed to 8 mm in the Japanese system) and a significant volume reduction of nearly 50%. The microphone weights only 0.4 g. In spite of this miniaturization, the performance characteristics of the microphone equal those of the Japanese model or are superior. The sound-pressure transfer function shows a very small ripple and the bandwidth amounts to approximately 10 kHz. Because of its high tuning and high no-load resonance frequency, the microphone is mostly insensitive to post-operational changes to the loading mass on the microphone membrane initiated by the covering skin of the auditory canal. The sound-pressure transfer factor at 1000 Hz is approximately 1.5 mV/Pa. Using different manufacturing technologies, this value can be increased in the range of 6-8 dB with a corresponding reduction in bandwidth. Due to the small mass, the microphone is highly insensitive to environmental mechanical disturbances. The module is made of pure titanium and is hermetically sealed according to Mil-Std 883 D. Full metal encapsulation and additional internal electronic components protect the microphone well against environmental electromagnetic influences (EMC).     

Estimation of the benefit of bone-anchored hearing aids

Implantable bone conduction hearing aids are a valuable alternative to conventional aids for those who cannot use a conventional air conduction aid or find it difficult to use because of an aural discharge, most commonly due to chronic otitis media. Previously reported series of the use of a bone-anchored hearing aid (BAHA) come from the originators of this device, and an independent report of their benefit and use, especially in previous air conduction aid users, would be of value. Twenty-three patients were evaluated at least 6 months after implantation of a BAHA. All 7 previous bone conduction aid users were delighted with their BAHA, reporting increased comfort and hearing benefit that was backed by audiometric evidence. Of the 16 individuals who previously used an air conduction aid, 11 (69%) were delighted users of their BAHA. Unfortunately, the other 5 (31%) reverted to solely using their air conduction aid. There was no obvious predictor as to how these individuals might have been identified prior to implantation. In particular, their pure tone thresholds, especially the bone conduction thresholds, were no different from those of the 11 BAHA users. However, in free field audiometry, the users gained superior benefit from their BAHA compared to their air conduction aid, whereas the nonusers did not. In conclusion, in all series to date, previous users of a conventional bone conduction aid have been delighted users of a BAHA and have gained superior audiometric benefit. This is not necessarily the case with previous air conduction aid users.(ABSTRACT TRUNCATED AT 250 WORDS)     

Speech intelligibility in noise with fast compression hearing aids

The effect of fast (syllabic) compression with overshoot reduction was studied in moderately hearing-impaired and in severely hearing-impaired listeners in quiet and in noisy situations. A test battery of daily masking noises was selected using multidimensional scaling techniques. Four relevant noises were selected: a multi-talker babble, the noise in an industrial plant, in a printing office and a city-noise background. The speech measurements show that only selected patients benefit from syllabic compression, i.e. listeners with a poor speech discrimination score. The effect in noisy surroundings was tested at the critical signal-to-noise ratio of each patient, showing whether they benefited from compression in the most critical condition or not. It turns out that the effect depends largely on the speech discrimination score and the modulation of the noise signal. When the speech discrimination score is good, compression tends to impair the results. When the speech discrimination score is poor, compression helps if the noise is modulated.     

The relationship between listening conditions and alternative amplification schemes for multiple memory hearing aids

OBJECTIVE: The aim of this study was to determine a relationship among selected listening conditions and amplification schemes that could be provided in a multiple memory hearing aid. DESIGN: The study consisted of three laboratory tests: 1) A screening test to select hearing impaired subjects who appeared to benefit from multiple amplification schemes. 2) A category scaling test to rank 16 amplification schemes in 15 listening conditions. The 16 schemes were simulated with a digital master hearing aid and comprised 5 linear systems and 11 compression characteristics. The 15 listening conditions comprised 6 listening environments combined with 2 or 3 response criteria. 3) A paired comparison test in which the two highest ranked amplification schemes were evaluated together with a reference linear frequency response (NAL) in a round-robin test. RESULTS: The screening test demonstrated that 21 hearing impaired people out of 25 with mild or moderate, flat or gently sloping hearing losses appeared to benefit from multiple amplification schemes. Age or audiometric factors did not serve to discriminate between those who selected different schemes and those who did not. In general, the NAL-response was preferred or was as good as any other for listening to speech in quiet, speech in reverberation, speech in babble-noise, and for naturalness of all listening environments. The subjects consistently selected an amplification scheme other than the NAL-response for four specific listening conditions. The findings suggest that substantial high-frequency compression is preferred for the ease of understanding multiple talkers, whose voices differ in overall level, in quiet environments. The annoyance of low-frequency background noise can be reduced by low-frequency compression, whereas a frequency response steeper than the NAL-response makes it easier to understand speech in low frequency background noise. Finally, a frequency response flatter than the NAL-response can be used to make a high-frequency background noise sound less annoying. CONCLUSION: Hearing aid users with mild or moderate, flat or gently sloping hearing losses, fitted with equal and sufficient variation in amplification, prefer different amplification schemes depending on the number of talkers, the background noise and the response criterion.     

Principle requirements of an electromechanical transducer for implantable hearing aids in inner hearing hearing loss. II: Clinical aspects]

In this retrospective study, 13 patients with subtle Lisfranc joint injuries were examined after a mean period of 23 months using clinical assessment, radiography and dynamic pedographic gait analysis. The aims were to identify the factors leading to a mobile flatfoot deformity, evaluate the functional and clinical outcome of these injuries, and draw practical conclusions for initial management and subsequent intervention. All patients showed a mobile flatfoot deformity, increased motion in the subtalar joint, increased load on the hindfoot, decreased load on the forefoot, and a prolonged contact phase during the stance phase. Radiographs revealed progressive osteoarthrosis in the joint and a residual displacement of the medial Lisfranc joint. An unstable medial Lisfranc joint results in the development of a mobile flatfoot. Initial treatment of a subtly displaced Lisfranc joint should consist of exact anatomical reduction and additional maintenance of the longitudinal arch of the foot. After failed initial treatment, early arthrodesis of the midfoot is recommended as a salvage procedure for the foot.     

Telephone communication with in-the-ear hearing aids using acoustic and electromagnetic coupling

The purpose of this study was to determine whether telephone communication was improved with electromagnetic coupling for in-the-ear hearing aid users with mild to moderate hearing losses. Each user adjusted his hearing aid gain to the level he determined to be best for telephone communication with each coupling method. Under these conditions, average word recognition scores in quiet and average high-frequency output levels measured at the tympanic membrane were not different for each coupling method. The ability to tolerate background noise was also studied. Background noise tolerance was not different for the two coupling methods. However, significantly greater levels of background noise were tolerated when telephone side-tone feedback was eliminated regardless of coupling method.     

Management and outcome: children fitted with hearing aids in Ireland

Rota Viral infection is recognised as a significant global public health concern causing large numbers of potentially preventable illnesses and deaths, especially among young ones of man and animals. The paper presents an overview of the epidemiology, control, treatment, virology, diagnosis and the zoonotic aspects of the problem. Problems for further research are identified.     

An adaptive noise canceller for hearing aids using two nearby microphones

An adaptive noise cancellation scheme based on two-stage adaptive filtering as proposed by Van Compernolle [Proceedings of the IEEE International Conference on Acoustics, Speech and Signal Processing (IEEE, New York, 1990)] was tested for two identical directional microphones mounted in an endfire configuration within a single behind-the-ear (BTE) hearing aid. Speech intelligibility tests were carried out with two normal hearing subjects and three hearing aid users with moderate hearing losses, in a realistic test environment using open set words and sentences. A significant improvement, on average more than 5 dB, of speech reception threshold (SRT) in background noise was obtained.     

The Valby Project: a survey of hearing in the elderly > or = 80 years of age not provided with hearing aids

Intravascular ultrasound is playing an increasingly important role in the clinical management of coronary interventions. In the past few years the technology for intracoronary ultrasound, in response to clinical pressure, has moved towards lower profile probes with improved handling. While new catheter designs are markedly improved on their predecessors, image quality has not seen significant gains due to the primitive nature of the ultrasound transducer designs. In this article, the potential for improving image quality by increasing the frequency and focusing the ultrasound beam is explored. Basic aspects of transducer implementation are discussed and the acoustic properties of vascular tissues and blood are reviewed. A variety of instruments are used to image coronary and femoral arteries at frequencies ranging from 40 to 200 MHz. These studies serve to illustrate the trade-offs in the development of high frequency IVUS systems. There would appear to be no fundamental reason why frequencies in excess of 50 MHz could not be implemented. Studies using prototype IVUS instruments in the 50 MHz range demonstrate significant improvements in image quality.     

Development and evaluation of a procedure for fitting multi-channel compression hearing aids

Hearing aids with multi-channel compression are often fitted on the basis of loudness scaling data obtained using narrow bands of noise or tones. Here, we report the development and evaluation of an alternative fitting procedure based on the use of speech signals. The parameters of the hearing aid (the gains in each channel for high and low input levels) are adjusted adaptively under computer control on the basis of the listener's responses. The goal is that speech at 85 dB SPL should be judged as 'loud', speech at 60 dB SPL should be judged as 'quiet', and speech at both levels should be judged as 'neither tinny nor boomy'. The procedure was evaluated using a two-channel compression hearing aid, the remote control of which allowed two programs to be stored. One program was based on our fitting procedure. The other was either based on the manufacturer's recommended full fitting procedure (which included loudness scaling with bands of noise), or was based on the audiogram alone, using the manufacturer's algorithm. After an acclimatization period of at least two weeks, subjects were then asked to fill in a questionnaire about their experiences with the two programs in different listening situations. The results generally indicated a preference for the program based on our adaptive fitting procedure. We also conducted laboratory measurements of speech intelligibility, in quiet and in a background of a single competing talker. These showed no clear difference between programs, although scores overall were very high. We conclude that our adaptive procedure gives very satisfactory results in everyday life. Parameter values giving good comfort also give good intelligibility. The procedure typically takes between five and 10 minutes per ear, which is quicker than most loudness scaling procedures.